RU2666525C2 - Photoelectric conversion device, ranging apparatus and information processing system - Google Patents

Abstract

FIELD: basic elements of electrical equipment.

SUBSTANCE: photoelectric conversion device comprising a first photoelectric conversion portion, which is a photodiode and is configured to generate electrons; and a second photoelectric conversion portion, which is a second photodiode and is configured to generate holes. Photoelectric conversion device further comprises: a charge-to-voltage conversion portion including an n-type first semiconductor region configured to collect the generated electrons, and a p-type second semiconductor region configured to collect holes, the charge-to-voltage conversion portion being configured to convert a charge that is based on the electrons and the holes to a voltage; a signal generation portion configured to generate a signal corresponding to the voltage, the signal generation portion including an amplification transistor; a first potential supply portion configured to apply a first potential to the anode of the first photodiode; and a second potential supply portion configured to supply a second potential to the cathode of the second photodiode, the second potential being higher than the first potential.

EFFECT: invention provides a device capable of improving the accuracy of signals generated on the basis of electrons and holes.

24 cl, 8 dwg

Description

BACKGROUND

Technical field

[0001] The present technical solution relates to a photoelectric conversion device.

State of the art

[0002] There is a range measuring apparatus (distance sensor) using a travel time (TOF) method. In the TOF method, a distance measuring target is illuminated by light emitted by a light source, and light reflected by the target is received. Based on the relationship between the speed of light and the time period from lighting to receiving light, the distance to the target is calculated. In this case, the light that was emitted by the light source for measuring range and reflected by the target is called a signal light. The received light includes, in addition to the signal light, light (ambient light) obtained from a light source different from a light source for measuring range, for example, natural light or artificial light. To increase the accuracy of the range measurement, it is useful to separate the ambient light and the signal light from each other.

[0003] Japanese Patent Laid-Open No. 2005-303268 (US Patent Application No. 2007/0103748) discloses a technical solution for removing a component corresponding to ambient light by an apparatus that performs a range measurement using a light detector. According to a second embodiment of this publication, the light detector includes a first photosensitive unit that has a suitable structure for extracting holes, and a second photosensitive unit that has a suitable structure for extracting electrons. Holes formed in the first photosensitive unit are held by the hole holding unit through the gateway, and electrons formed in the second photosensitive unit are held by the electron holding unit through the gateway. The holes held by the hole holding unit and the electrons held by the electron holding unit are recombined by the recombination unit, and the carriers remaining after the recombination are extracted as object carriers through the output unit.

[0004] Japanese Patent Laid-Open No. 2008-89346 (US Patent Application No. 2008/0079833) discloses a technical solution for removing noise from background lighting (ambient light) by selectively controlling the conductivity of a plurality of charge storage sections and a plurality of capacitors to extract a component the difference in charge stored in the plurality of charge storage sections.

SUMMARY OF THE INVENTION

[0005] The photoelectric conversion device in accordance with the present disclosure includes a first photoelectric conversion section configured to form electrons; a second photovoltaic conversion section configured to form holes; a charge to voltage conversion section including a first n-type semiconductor region configured to collect electrons and a p-type second semiconductor region configured to collect holes; a charge to voltage conversion section is configured to convert a charge, which is based on electrons and holes, in voltage; and a signal conditioning portion configured to generate a signal corresponding to a voltage, the signal conditioning portion includes a gain transistor.

[0006] Further features of the present invention will become apparent from the following description of illustrative embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1A and 1B are diagrams for describing a photoelectric conversion device, a ranging apparatus, and an information processing system.

[0008] FIG. 2 is a diagram for describing the operation of a photoelectric conversion device.

[0009] FIG. 3 is a diagram for describing a circuit of a photoelectric conversion device.

[0010] FIG. 4A-4C are diagrams for describing the operation of a photoelectric conversion device.

[0011] FIG. 5A-5D are diagrams for describing the structure of a photoelectric conversion device.

[0012] FIG. 6A-6D are diagrams for describing structures of a photoelectric conversion device.

[0013] FIG. 7 is a diagram for describing a circuit of a photoelectric conversion device.

[0014] FIG. 8 is a diagram for describing the operation of a photoelectric conversion device.

DESCRIPTION OF EMBODIMENTS

[0015] An embodiment provides a photoelectric conversion device capable of improving signal accuracy.

[0016] In the technical solution in accordance with Japanese Patent Laid-Open No. 2005-303268 (US Patent Application No. 2007/0103748), insufficient attention was paid to the motions of electrons and holes when using a photoelectric conversion unit (photosensitive unit) for holes and a photoelectric conversion unit (photosensitive block) for electrons. Thus, it is possible that electrons and holes will not be efficiently assembled, and that the accuracy of signals generated from electrons and holes will decrease. Accordingly, an embodiment provides a photoelectric conversion device capable of improving the accuracy of signals generated from electrons and holes.

[0017] The photoelectric conversion device in accordance with the first aspect of the embodiment includes a first photodiode that forms electrons, a second photodiode that forms holes, a first n-type semiconductor region that collects electrons formed by the first photodiode, and a second p- semiconductor region a type that collects holes formed by the second photodiode, a signal generating portion with which the first semiconductor region and the second semiconductor region are connected together, a first potential supply section that feeds the first potential to the anode of the first photodiode, and a second potential supply section that supplies the second potential to the cathode of the second photodiode. The second potential is higher than the first potential.

[0018] In accordance with a first aspect, there is provided a photoelectric conversion device capable of improving the accuracy of signals generated from electrons and holes.

[0019] In the technical solution in accordance with Japanese Patent Laid-Open No. 2008-89346 (US Patent Application No. 2008/0079833), switching interference (kCT noise) generated during selective switching of the conductivity of a plurality of charge storage sections and a plurality of capacitors degrades the signal ratio -noise, as described in paragraphs 0109 and 0110. Thus, in this technical solution, it is difficult to accurately extract the difference component of the charge stored in the plurality of charge storage sections. Accordingly, an embodiment provides a photoelectric conversion device that accurately generates a signal corresponding to a charge difference between a plurality of photoelectric conversion sections.

[0020] The photoelectric conversion device in accordance with the second aspect of the embodiment includes a first photoelectric conversion section that forms electrons, a second photoelectric conversion section that forms holes, a first n-type semiconductor region that collects electrons formed by the first photoelectric conversion section , a second p-type semiconductor region that collects holes formed by the second portion of the photoelectric conversion azane, and a signal generating portion with which the first semiconductor region and the second semiconductor region are connected together. The difference between the first potential supplied to the first semiconductor region and the second potential supplied to the second semiconductor region during the reset period is less than 0.10 V.

[0021] In accordance with a second aspect, a photoelectric conversion device is provided that accurately generates a signal corresponding to a charge difference between a plurality of photoelectric conversion sections.

[0022] In the technical solution in accordance with Japanese Patent Laid-Open No. 2005-303268 (US Patent Application No. 2007/0103748), insufficient attention has been paid to the configuration of the recombination unit when the hole holding unit and the electron holding unit are provided separately. Accordingly, an embodiment provides a photoelectric conversion device capable of receiving, in a simple configuration, a signal corresponding to a difference in a signal charge generated by a plurality of photoelectric conversion sections.

[0023] The photoelectric conversion device according to the third aspect of the embodiment includes a first photoelectric conversion section that forms electrons, a second photoelectric conversion section that forms holes, a first n-type semiconductor region that collects electrons formed by the first photoelectric conversion section , a second p-type semiconductor region that collects holes formed by the second portion of the photoelectric conversion azane, and a signal generating portion with which the first semiconductor region and the second semiconductor region are connected together. The first semiconductor region and the second semiconductor region are connected to each other via a conductor.

[0024] In accordance with a third aspect, there is provided a photoelectric conversion device capable of receiving in a simple configuration a signal corresponding to a difference in a signal charge generated by a plurality of photoelectric conversion sections.

[0025] In the technical solution in accordance with Japanese Patent Laid-Open No. 2005-303268 (US Patent Application No. 2007/0103748), the timing control unit controls the applied voltage, and thereby the individual gateways can be opened alternately. However, it is difficult to accurately control the applied voltage at high speed. In particular, if the on / off delay between the two gateways is large, the accuracy of the signals generated on the basis of electrons and holes may decrease. Accordingly, an embodiment provides a photoelectric conversion device capable of improving the accuracy of signals generated from electrons and holes.

[0026] The photoelectric conversion device according to the fourth aspect of the embodiment includes a first photoelectric conversion section that forms electrons, a second photoelectric conversion section that forms holes, a first transfer section that transfers electrons formed by the first photoelectric conversion section to the first an n-type semiconductor region, and a second transfer portion that transfers holes formed by the second portion of the photoelectric conversion to the second p-type semiconductor region. The first transfer section and the second transfer section are connected to the same node, the first transfer section is turned on and the second transfer section is turned off in response to applying the first potential to the node, and the first transfer section is turned off and the second section the transfer is turned on in response to the supply of the second potential to the node.

[0027] In accordance with a fourth aspect, there is provided a photoelectric conversion device capable of improving the accuracy of signals generated from electrons and holes.

[0028] In the technical solution in accordance with Japanese Patent Laid-Open No. 2005-303268 (US Patent Application No. 2007/0103748), insufficient attention was paid to how the photoelectric conversion unit (photosensitive unit) for holes and the photoelectric conversion unit (photosensitive unit) are placed ) for electrons. Accordingly, an embodiment provides a photoelectric conversion device that, with a simple configuration, generates signals based on electrons and holes.

[0029] The photoelectric conversion device according to the fifth aspect of the embodiment includes a first photodiode that forms electrons, a second photodiode that forms holes, a first n-type semiconductor region that collects electrons formed by the first photodiode, a second p- semiconductor region a type that collects holes formed by the second photodiode, and a signal generation portion with which the first semiconductor region and the second semiconductor region are connected together. The third p-type semiconductor region that makes up the anode of the first photodiode and the fourth n-type semiconductor region that makes up the cathode of the second photodiode are electrically isolated from each other by a p-n junction.

[0030] In accordance with a fifth aspect, a photoelectric conversion device is provided which, with a simple configuration, generates a signal based on electrons and holes.

[0031] Hereinafter, an embodiment will be described in detail with reference to the attached drawings. In the following description and in the attached drawings, like elements are denoted by like numbers throughout all of the plurality of figures. Thus, the same elements will be described with reference to a plurality of figures, and a description of the elements indicated by the same reference numbers is omitted accordingly.

[0032] With reference to FIG. 1A, a description will be given of a photoelectric conversion device 11 and an information processing system SYS including a photoelectric conversion device 11. The information processing system SYS includes a range measuring apparatus 1 and may further include at least any component from the information processing apparatus 2, the control apparatus 3, the drive apparatus 4, the image capturing apparatus 5, the display apparatus 6, and the communication apparatus 7. In the information processing system SYS, the photoelectric conversion device 11 is included in the range measuring apparatus 1. The image capturing apparatus 5 may include a photoelectric conversion device different from the photoelectric conversion device 11 of the ranging device 1. Alternatively, the photoelectric conversion device 11 may function as a photoelectric conversion device of the range measuring apparatus 1 and a photoelectric conversion device of the image capturing apparatus 5. Examples of application of the SYS information processing system will be described below.

[0033] The distance measuring apparatus 1 includes a light receiving unit 10. The ranging device 1 may include a light emitting unit 20. The light receiving unit 10 includes a photoelectric conversion device 11 and an optical system 12 that controls incident light on the photoelectric conversion device 11 . The light emitting unit 20 includes a light emitting device 21 serving as a light source, and an optical system 22 that controls the outgoing light from the light emitting device 21. An LED can be used as the light emitting device 21 because it is capable of periodically flashing at high speed. The wavelength of the light emitted by the light emitting device 21 may be infrared radiation in order to reduce the mixing of colors with ambient light, which includes mainly visible light. Infrared radiation can hardly be visually identified by a person, and thus is convenient to use. However, the embodiment is not limited to infrared light. Each of the optical systems 12 and 22 includes a lens, aperture, a mechanical shutter, a scattering plate, an optical low-pass filter, a wavelength selection filter, etc. For example, the optical system 12 may include a filter having a higher transmittance for infrared light than for visible light. The range measuring apparatus 1 illustrated in FIG. 1A includes optical systems 12 and 22, but at least any of these optical systems may be omitted. In the case of using laser radiation as a light source, the optical system 22 may include a scanning optical system for scanning the light emitted by the light emitting unit 20 in the direction of a predetermined area. The range measuring apparatus 1 may include a control unit 30 that is connected to at least one component from the light receiving unit 10 and the light emitting unit 20. The control unit 30 drives and / or controls at least one component from the light receiving unit 10 and the light emitting unit unit 20. A control unit 30 in accordance with an embodiment that is connected to both the light receiving unit 10 and the light emitting unit 20, is capable of driving and / or controlling both the light receiving unit 10 and etoizluchayuschim unit 20, and more particularly, is able to drive and / or control both of them simultaneously. The control unit 30 is also capable of operating in response to a signal received from the information processing apparatus 2. The range measuring apparatus 1 may include a processing unit 40 that is connected to the light receiving unit 10. The processing unit 40 processes the signals output from the light receiving unit 10. The signals processed by the processing unit 40 can be transmitted to the information processing device 2. At least one of the control unit 30 and the processing unit 40 is capable of operating in response to a signal received from the information processing apparatus 2.

[0034] The light 81 emitted by the light emitting unit 20 is directed to the target 9, reflected from the target 9 and received as a signal light 82 by the light receiving unit 10. The difference based on the distance from the distance measuring apparatus 1 to the target 9 and the speed of light (3 × 10 ⁸ m / s) is formed between the time of light emission in the light-emitting unit 20 and the time of light reception in the light-receiving unit 10. Using the physical quantity corresponding to the detected time difference, the distance from the distance measuring apparatus 1 to the target 9 can be obtained, or information based on the distance from the ranging apparatus 1 to the target 9, for example, image data. The range measuring apparatus 1 is a range measuring apparatus using a travel time (TOF) method. The degree of the time difference described above can be detected by measuring the phase difference of the light, which periodically changes, or the number of light pulses. The large interval between the light emitting unit 20 and the light receiving unit 10 can make the ranging algorithm complicated, and thus the interval between the light emitting unit 20 and the light receiving unit 10 can be set shorter than the interval corresponding to the desired accuracy of the ranging. For example, the interval between the light emitting unit 20 and the light receiving unit 10 is set to 1 m or less.

[0035] The light receiving unit 10 includes not only the signal light 82, but also the ambient light 83 received from the light source, different from the light emitted by the light emitting device 21 as a light source. Ambient light source 83 is natural light or artificial light. Ambient light 83 is a noise component when ranging is performed. Thus, if the ratio of the ambient light 83 to the received light is high, the dynamic range of the signal based on the signal light 82 decreases or the signal-to-noise ratio decreases, and it is difficult to accurately obtain distance information from the signal light 82. The photoelectric conversion device 11 according to with an embodiment, it is capable of removing at least a portion of the component resulting from the ambient light 83 from a signal generated based on the light received by the photoelectric device 11 wow conversion. Accordingly, the accuracy of the range measurement can be improved. Although details will be described below, in an embodiment, at least a portion of the component resulting from ambient light 83 is removed by using a signal corresponding to a difference in signal charge generated by a plurality of photoelectric conversion sections. In addition, when using electrons and holes as a signal charge, the difference in charge value can be accurately detected by using a simple structure. Accordingly, the accuracy of the range measurement can be improved.

[0036] An overview of the photoelectric conversion device 11 in accordance with an embodiment will be described with reference to FIG. 1B. The photoelectric conversion device 11 includes an array of 110 cells on a semiconductor substrate 100. An array of 110 cells includes a plurality of photoelectric conversion cells 111 that are arranged in a matrix formed of a plurality of rows and a plurality of columns. The photoelectric conversion device 11 may also include connecting lines 120 rows, connecting lines 130 columns, a driving part 140, a controlling part 150, a signal processing part 160, a scanning part 170, and an output part 180 on the semiconductor substrate 100. A plurality of photovoltaic cells 111 in an array of 110 cells are connected to the drive portion 140 via row connecting lines 120 located on the semiconductor substrate 100. The drive portion 140 selectively inputs control signals, such as transfer signals or reset signals, into a plurality of photoelectric conversion cells 111 in series or simultaneously. The plurality of photovoltaic cells 111 in the array 110 cells are connected to the signal processing portion 160 via column connecting lines 130 located on the semiconductor substrate 100. The signal processing portion 160 processes the signals output from the photoelectric conversion cells 111 via column connecting lines 130. The signal processing portion 160 may include, for each column of the array of cells 110, a CDS circuit, a gain circuit, and an analog-to-digital (AD) conversion circuit. The scanning part 170 causes sequentially to output signals that were issued from the array of 110 cells to the signal processing part 160 through separate connecting lines 130 of the columns and processed by the signal processing part 160, and which correspond to the individual columns, from the signal processing part 160 to the output part 180. The output part 180 outputs the signals received from the signal processing part 160 outside the photoelectric conversion device 11 and may include an amplification circuit, a protection circuit, and an electrode for establishing a connection with the external circuit. The control part 150 generates control signals and controls the timing of the operation of the drive part 140, the signal processing part 160, the scan part 170 and the output part 180 by using control signals.

[0037] An array of lenses on the microcircuit (array of microlenses) and a wavelength filter can be provided on the side of the light incident surface of the semiconductor substrate 100. The side of the light incident surface can be identical to the side on which the connecting lines 120 of the row and the connecting lines 130 of the columns are provided on the semiconductor substrate 100 (front surface side). By this configuration, a photoelectric conversion device with irradiation of the front surface can be obtained. If the side of the light incidence surface is opposite to the side on which the connecting lines 120 of the rows and the connecting lines 130 of the columns are provided on the semiconductor substrate 100 (side of the back surface), a photoelectric conversion device with irradiation of the back surface can be obtained.

[0038] FIG. 2 illustrates eight-row operation in the case where an array of 110 cells includes eight rows of photoelectric conversion cells 111. In the example illustrated in FIG. 2, progressive scanning is performed on lines from the first line R1 to the eighth line R8. Alternatively, interlaced scanning may be performed.

[0039] The control period Tdr for one photoelectric conversion cell 111 includes a reset period Trs in which the reset operation is performed, an accumulation period Tac in which the accumulation operation for accumulating charge based on the signal light 82 is performed, and a reading period Tsr in which a read operation is performed to read the signals based on the accumulated charge. The reading period Tsr can also be called the period in which the output from the cell of the photoelectric conversion is carried out in the connecting line of the columns. The control period Tdr may also include a period in which another desired operation is performed. In this example, a plurality of photovoltaic cells 111 belonging to the same row are simultaneously controlled for one control period Tdr. Signals output from a plurality of photovoltaic cells 111 belonging to the same line of the cell array 110 are processed by the signal processing part 160 and output to the output part 180, as described above with reference to FIG. 1B.

[0040] A frame period is a period in which reset operations, accumulation operations, and read operations are performed on all rows of photoelectric conversion cells 111 constituting an array of 110 cells. For example, the start point of the first period of frame F1 is the point in time at which the reset operation begins on the first line R1, and the end point of the first period of frame F1 is the point in time at which the read operation in the photoelectric conversion cells 111 in the eighth line R8 is downloaded. The starting point of the second period of frame F2 is the point in time at which the reset operation in the first line R1 begins for the first time after the read operation in the first line R1 in the first period of frame F1 has ended. The endpoint of the second period of frame F2 is the point in time at which the read operation in the eighth line of R8 ends for the first time after the read operation in the eighth line of R8 in the first period of frame F1 ends.

[0041] As illustrated in FIG. 2, the accumulation operations in a plurality of lines (in this example, the third to fourth row) are performed in parallel, and thus, the accumulation period can be extended, and the output of signals received during the accumulation period can be increased. Even when the accumulation operations in many lines are performed in parallel, the signals in many lines can be separated from each other if the synchronization of the read operation is different among the lines.

[0042] Furthermore, as a result of performing the sequence of operations, so that part of the first period of frame F1 overlaps part of the second period of frame F2, as illustrated in FIG. 2, the frame rate may be increased, or one frame period may be extended. Thus, in FIG. 2, while the read operations in the first to fourth rows are completed in the first period of the frame F1, the reset operation and the accumulation operation in the first row begin.

[0043] An embodiment is not limited to this example. After the reset operation, the accumulation operation and the read operation in one line have all been completed, the reset operation, the accumulation operation and the read operation in the next line can be started. Alternatively, after the read operation in the last line (in the eighth line) has been completed, a reset operation in the first line can be started.

[0044] Next, a description will be given of an illustrative structure of each photoelectric conversion cell 111. FIG. 3 illustrates an equivalent circuit of a photoelectric conversion cell 111. In FIG. The 3 elements included in the photoelectric conversion cell 111 as a repeating array block are surrounded by a dash-dot line. It should be noted that with respect to elements surrounded by a dashed line, part of the elements may be located outside the array 110 cells (for example, the drive part 140).

[0045] The photoelectric conversion cell 111 includes a photoelectric conversion section 301 and a photoelectric conversion section 302. The photoelectric conversion section 301 forms electrons as a signal charge through the photoelectric conversion, while the photoelectric conversion section 302 forms holes as a signal charge through the photoelectric conversion. Thus, the positive / negative sign of the signal charge generated by the photoelectric conversion section 301 is opposite to the sign of the signal charge formed by the photoelectric conversion section 302. However, the photoelectric conversion section 301 forms holes, as well as electrons, and the photoelectric conversion section 302 forms electrons, as well as holes. Each of the photoelectric conversion sections 301 and 302 is a p-n-photodiode or p-i-n-photodiode and may be a photodiode with an in-depth transition in terms of reducing the dark current. The use of in-depth transition photodiodes as the photoelectric conversion sections 301 and 302 is advantageous in terms of reducing the dark current compared to the case of using photo shutters as the photoelectric conversion sections 301 and 302 and increasing the signal-to-noise ratio, which is important for receiving weak signal light. The photodiode serving as the photoelectric conversion section 301 includes a cathode 201, which is an n-type semiconductor region in which electrons are the majority of carriers, and an anode 211, which is a p-type semiconductor region, in which electrons are a minority of carriers. The photodiode serving as the photoelectric conversion section 302 includes an anode 202, which is a p-type semiconductor region in which holes are the majority of carriers, and a cathode 212, which is an n-type semiconductor region, in which holes are a minority of carriers.

[0046] The photoelectric conversion cell 111 includes a capacitor section 307 capable of holding electrons as a signal charge generated by the photoelectric conversion section 301, and a capacitor section 310 capable of holding holes as a signal charge formed by the photoelectric conversion section 302.

[0047] The capacitor section 307 includes a support unit 217 and a collection unit 207. The collecting unit 207 collects electrons as a signal charge generated by the photoelectric conversion section 301. The capacitor section 307 is configured so that a potential difference corresponding to the amount of charge held by the capacitor section 307 appears between the collection section 207 and the reference section 217. Thus, the capacitor section 307 functions as a section for converting charge to voltage, which converts the amount of charge into voltage . The capacitor section 310 includes a support assembly 200 and a collection assembly 210. The collection unit 210 collects holes as a signal charge generated by the photoelectric conversion section 302. The capacitor section 310 is configured so that a potential difference corresponding to the amount of charge held by the capacitor section 310 appears between the collection unit 210 and the reference node 200. Thus, the capacitor section 310 functions as a section for converting the charge into voltage, which converts the amount of charge into voltage .

[0048] Each of the capacitor sections 307 and 310 has a pn junction diode structure. The reference assembly 217 and the collection assembly 210 are p-type semiconductor regions, while the reference assembly 200 and the collection assembly 207 are n-type semiconductor regions. The nodes 207 and 210 collection, which hold the signal charge, are floating nodes that are electrically floating. The semiconductor regions constituting the collection nodes 207 and 210 are regions of diffusion of impurities in a floating state, that is, floating diffuse regions. Node assembly 207, which is an n-type semiconductor region, can collect electrons as a signal charge and hold electrons. The collection unit 210, which is a p-type semiconductor region, can collect holes as a signal charge and hold holes. Although the details will be described below, the photoelectric conversion device 11 is able to operate in such a way that the signal charge is selectively held by one of the collection nodes 207 and 210.

[0049] The photoelectric conversion cell 111 includes a transfer portion 303 for efficiently collecting electrons among electrons and holes formed by the photoelectric conversion portion 301 in the collection portion 207 of the capacitor section 307. In addition, the photoelectric conversion cell 111 includes a transfer portion 306 for efficiently collecting holes among the electrons and holes formed by the photoelectric conversion section 302 in the collecting section 210 of the capacitor section 310. Thus, the collecting sections 207 and 210 can also ut referred to as nodes, in which the signal charge is transferred from the portions 301 and 302 of photoelectric conversion respectively. Since the collection units 207 and 210 are capable of holding charge transferred from the photoelectric conversion sections 301 and 302, the collection units (capacitor sections) may also be referred to as charge holding sections.

[0050] Each of the transfer portions 303 and 306 has a MIS gate structure. More specifically, the transfer portions 303 and 306 have a multilayer structure including a semiconductor region (channel region), an insulating gate film, and a gate electrode. Thus, the transfer portions 303 and 306 may also be referred to as transfer gates. When the transfer portion 303 is in the on state (in the conductive state), the inversion forms an n-type channel in the semiconductor region. When the transfer portion 306 is on, the inversion forms a p-type channel in the semiconductor region. Thus, the conductivity types of the transfer portions 303 and 306 are different from each other.

[0051] In this example, the gate electrode of the transfer portion 303 and the gate electrode of the transfer portion 306 are connected together with the transfer portion 218. The transfer unit 218 is connected to the transfer signal output portion 428, and the transfer signal TX1 is inputted from the transfer signal output portion 428 to the transfer unit 218. Sites 303 and 306 transfer have different types of conductivity and are configured to work in an additional order. Thus, the transfer portion 306 is in an off state (non-conductive state) at a time when the transfer portion 303 is in an on state in response to the transfer signal TX1, and the transfer portion 306 is in an on state at a time when the transfer portion 303 is in off in response to TX1 transfer signal.

[0052] The threshold can be set so that both portions 303 and 306 are turned off when the transfer unit 218 has a predetermined potential. The predetermined potential may be the potential between the potential at which the transfer portion 303 is on and the transfer portion 306 is off and the potential at which the transfer portion 303 is off and the transfer portion 306 is on. Such a predetermined potential is determined in accordance with the potential in the semiconductor region in the MIS gate structure and the threshold of the MIS gate structure. The difference between the high (High) potential level at which the transfer section 303 is in the on state and the medium (Mid) potential level at which the transfer section 303 is in the off state is, for example, 1-5 V. The difference between the low ( Low) the potential level at which the transfer section 306 is in the on state and the average potential level at which the transfer section 303 is in the off state is, for example, 1-5 V. A high potential level can be set equal to the potential potential (negative potential), which is higher than zero (GND) potential (0 V), and a low level of potential can be set equal to potential (negative potential), which is lower than zero potential. For example, the average potential level can be set equal to zero potential. Both high and low potential levels can be set equal to positive potentials, or both high and low potential levels can be set equal to negative potentials to reduce the scale of the circuit.

[0053] Alternatively, the transfer portions 303 and 306 can be connected to different transfer nodes, and the on / off states of the transfer portions 303 and 306 can be controlled by using transfer signals independent of each other. However, it may be better to connect the transfer portions 303 and 306 to the same transfer unit 218 and apply the same transfer signal TX1 to the gate electrodes of the transfer portions 303 and 306. Accordingly, the accuracy of synchronization of the on / off state of the transfer portions 303 and 306 can be improved. In addition, since the transfer portions 303 and 306 can be controlled by the same control circuit and the connecting line, the configuration of the photoelectric conversion device 11 can be simplified.

[0054] In the above manner, the collection unit 207 is connected to the cathode 201 through the transfer portion 303. In addition, the collection unit 210 is connected to the anode 202 through the transfer portion 306.

[0055] The collection unit 207 may not be connected to the cathode 201 via an active element, such as a transfer portion 303. In addition, the collection unit 210 may not be connected to the anode 202 via an active element, such as a transfer portion 306. For example, by maintaining a suitable relationship between the potential in the photoelectric conversion section 301 and the potential in the capacitor section 307, the electrons formed by the photoelectric conversion section 301 can be collected in the collection section 207, even if the transfer section 303 is omitted. In addition, by maintaining a suitable relationship between the potential in the photoelectric conversion section 302 and the potential in the capacitor section 310, the holes formed by the photoelectric conversion section 302 can be assembled in the collection unit 210, even if the transfer section 306 is omitted. In addition, the photoelectric conversion section 301 can also be configured to function as a capacitor section 307 having a capacitance corresponding to its capacitance, and the photoelectric conversion section 302 can also be configured to also function as a capacitor section 310 having a capacitance corresponding to its capacitance transition. For example, a region of high concentration in which the concentration of an n-type impurity is higher than in another region can be provided in a part of the semiconductor region of an n-type photodiode, and a region of high concentration can be used as a collection unit. As an alternative to switching between the transfer and the absence of charge transfer from the photoelectric conversion sections 301 and 302, the switching between the discharge and the absence of discharge from the photoelectric conversion sections 301 and 302 from the discharge sections connected to the photoelectric conversion sections 301 and 302 can be used. However, switching between the transfer and the absence of charge transfer using the transfer portions 303 and 306 enables accurate charge control compared with the case of not using the transfer portions 303 and 306.

[0056] The reference potential supply section 411 is connected to the anode 211 of the photoelectric conversion section 301 and the reference node 217 of the capacitor section 307. The reference potential VF1 is supplied from the reference potential supply section 411 to the anode 211 of the photoelectric conversion section and the reference section 217 of the capacitor section 307. The reference potential supply section 412 is connected to the cathode 212 of the photoelectric conversion section 302 and the reference node 200 of the capacitor section 310. The reference potential VF2 is supplied from the reference supply section 412 of building together at the cathode 212 of the photoelectric conversion portion 302 and support assembly 200 capacitor portion 310.

[0057] As described above, the photoelectric conversion section 301 also forms holes, but the holes discharge to the side of the anode 211. The photoelectric conversion section 302 also forms electrons, but the electrons discharge to the side of the cathode 212.

[0058] Node 207 collecting capacitor section 307 and node 210 collecting capacitor section 310 are connected together with node 220 detection. The potential corresponding to the number of electrons transferred from the photoelectric conversion section 301 to the capacitor section 307 and the capacitance of the capacitor section 307 appear in the collection unit 207 and the detection unit 220. In addition, a potential corresponding to the number of holes transferred from the photoelectric conversion section 302 to the capacitor section 310 and the capacitance of the capacitor section 310 appears in the collection unit 210 and the detection unit 220. As a result, the potential, which is a combination of the potential that can appear in the detection unit 220 due to the electrons collected by the collection unit 207, and the potential that can appear in the detection unit 220 due to the holes collected by the collection unit 210, appears in the detection unit 220.

[0059] The collection units 207 and 210 are electrically connected to each other. The electrical connection between the collection nodes 207 and 210 is established by means of a conductor (electrical conductor). Typically, collection nodes 207 and 210 are directly connected to each other via a conductor. The conductor has a specific conductivity of 10 ⁴ cm / m or more (specific resistance 10 ^{to 4} ohm · m or less). The insulator has a specific conductivity of 10 ^-7 S / m or less (specific resistance 10 ⁷ Ohm · m or more). The semiconductor has a specific conductivity between 10 ^-7 S / m and 10 ⁴ S / m (specific resistance between 10 ^{- 4} Ohm · m and 10 ⁷ Ohm · m). Examples of the conductor include metal, a metal-containing compound, graphite, and polycrystalline silicon. It is also believed that silicon with a high concentration of impurities (10 ¹⁹ / cm ³ or more) has an electrically conductive behavior. Since the collection nodes 207 and 210 are connected to each other through a conductor, charge is freely transmitted and received between the collection nodes 207 and 210. This reduces the time until the potentials in the nodes 207 and 210 of the collection become static.

[0060] It is believed that the following phenomenon will occur in a transient manner. First, a difference arises between the number of electrons collected by the collection unit 207 and the number of holes collected by the collection unit 210. In accordance with this difference, a potential difference occurs between the collection nodes 207 and 210. Electrons move between the collection nodes 207 and 210 through the conductor to reduce the potential difference. Then, the electrons and holes recombine (pair annihilation) in the collection unit 210. Accordingly, a potential corresponding to the amount of charge as a difference between the number of electrons collected by the collection unit 207 and the number of holes collected by the collection unit 210 arises in the detection unit 220.

[0061] In this example, since the collection nodes 207 and 210 are directly connected to each other via a conductor, the potentials in the collection nodes 207 and 210 and the detection section 220 can be considered the same. In addition, for example, a switch may be provided between the collection unit 207 and the detection unit 220 and / or between the collection unit 210 and the detection unit 220. Accordingly, control can be temporarily performed such that at least two nodes from the collection nodes 207 and 210 and the detection node 220 have different potentials.

[0062] The potential in the detection node 220 is represented as VN, the potential in the collection node 207 is represented as VN1, and the potential in the collection node 210 is represented as VN2. Moreover, individual potentials VN, VN1 and VN2 are variable potentials. As described above, in the embodiment, the collection nodes 207 and 210 are connected together with the detection node 220, and thus, VN≈VN1≈VN2 is satisfied. In terms of ease of electron collection of the cathode 201 of the photoelectric conversion section 301 by the collection section 207, it may be better when VF1 <VN1. Furthermore, from the viewpoint of ease of collecting holes of the anode 202 of the photoelectric conversion section 302 by the collection unit 210, it may be better when VN2 <VF2. If VF1 <VN1 and VN2 <VF2, then VF1 <VF2, since VN1 = VN2. A ratio in which the reference potential VF2 is higher than the reference potential VF1 (VF1 <VF2) is more advantageous to increase the accuracy of the range measurement than the ratio in which the reference potential VF2 is equal to or lower than the reference potential VF1 (VF1≥VF2 ) Thus, charge collection efficiency is increased, and high speed operation and very accurate signal collection can be realized. From a practical point of view, in one embodiment, the potential difference between the reference potentials VF1 and VF2 may be 0.10 V or more. To this end, in this example, reference potential supply sections 411 and 412 are provided separately. The potential difference between the reference potentials VF1 and VF2 is usually 1 V or more and 5 V or less. The reference potential VF1 can be set below the zero potential 0 V (VF1 <GND), and the reference potential VF2 can be set above the zero potential 0 V (GND <VF2). Thus, the reference potential VF1 may be a negative potential, and the reference potential VF2 may be a positive potential.

[0063] The detection unit 220 is connected to a signal generating portion 315. In this example, the signal conditioning portion 315 is a MOS transistor (gain transistor) including a gate, a source, and a leak. The detection unit 220 is connected to the gate of the signal generating portion 315 (with a gain transistor).

[0064] A leak of the signal generating portion 315 is connected to the power supply portion 432, and the potential of the power source VDD is supplied to it from the power supply portion 432. The source of the signal generating portion 315 is connected to the direct current source 430 via a MOS transistor 316 (selection transistor), and the signal generating portion 315 constitutes a source follower circuit together with the direct current source 430. During the read operation, the selection signal SL is output from the selection signal supply portion 426 connected to the gate of the selection transistor 316, so that the selection transistor 316 is turned on. Accordingly, the signal generating portion 315 generates a pixel signal corresponding to the potential in the detection unit 220, and outputs the pixel signal to the output line 431, which is included in the column connecting lines 130 illustrated in FIG. 1B.

[0065] In this example, an electric low-pass filter 433 is provided between the detection unit 220 and the signal generating portion 315. With the provided electric low-pass filter 433, the output from the signal generating portion 315 can be stabilized, and the accuracy of the range measurement can be increased even if the potential in the detection portion 220 fluctuates. An electric low-pass filter 433 may be formed of a resistor connected in series with the gate of the gain transistor and a capacitor connected in parallel with the gate, but the configuration is not limited to this. Alternatively, an electric low-pass filter 433 may be omitted.

[0066] The reset potential supply portion 413 is connected to the collection nodes 207 and 210 through a MOS transistor 313 (reset transistor). The reset potential supply portion 413 provides a reset potential VS1. The reset signal RS1 issued from the reset signal output portion 423 to the gate of the reset transistor 313 causes the reset transistor 313 to be on. Accordingly, the potential VS11 corresponding to the reset potential VS1 is supplied from the reset potential supply portion 413 to the collection unit 207. Thus, the potential VN1 in the collection node 207 becomes equal to the potential VS11 (VN1 = VS11). In addition, the potential VS12 corresponding to the reset potential VS1 is supplied from the reset potential supply portion 413 to the collection unit 210. Thus, the potential VN2 in the collection node 210 becomes equal to the potential VS12 (VN2 = VS12).

[0067] During the reset operation, the potential VS11 is supplied to the collecting unit 207 of the capacitor section 307, and thereby the electrons held by the capacitor section 307 are discharged to the reset potential supply section 413. The potential VS12 is supplied to the collection unit 210 of the capacitor section 310, and thereby the holes held by the capacitor section 310 are discharged to the discharge potential supply section 413.

[0068] In order to increase the accuracy of the range measurement, it is advantageous that the potential difference between the potential VS11 and the potential VS12 is less than 0.10 V, compared with the case in which the potential difference between them is 0.10 V or more. When the potential difference VS11 and VS12 is less than 0.10 V with respect to the collection units 207 and 210 connected together with the detection unit 220, the operation during the accumulation period Tac after the reset period Trs can be stabilized. To make the potential difference between the potentials of VS11 and VS12 less than 0.10 V, the nodes 207 and 210 of the collection can be connected to each other through a conductor having a high conductivity. Furthermore, in order to make the potential difference between the potentials of VS11 and less than 0.10 V VS12, a resistor that makes the difference between the potentials of VS11 and VS12 equal to 0.10 V or more cannot be located between the collection nodes 207 and 210. It should be noted that a small potential difference of less than 0.10 V is permissible, which may be caused by an inevitably generated resistance or a manufacturing error.

[0069] In this example, the potential VS11 is applied to the collection unit 207, and at the same time, the potential VS12 is applied to the collection unit 210. A switch may be provided between the reset signal output portion 423 and the collection unit 207 and between the reset signal output portion 423 and the collection unit 210. In this case, the synchronization of the application of the potential VS11 to the collection node 207 may differ from the synchronization of the application of the potential VS11 to the collection node 210.

[0070] The potential of VS11 may be higher than the reference potential of VF1 (VF1 <VS11). In this case, the electron collection efficiency of the collection unit 207 after the reset period Trs can be improved. In addition, the potential of VS12 may be lower than the reference potential of VF2 (VS12 <VF2). In this case, the hole collection efficiency of the collection unit 210 after the discharge period Trs can be improved. As described above, when VS11 = VS12 = VS1, the reset potential VS1 can be the potential between the reference potential VF1 and the reference potential VF2 (VF1 <VS1 <VF2) to satisfy both expressions VF1 <VS11 and VS12 <VF2.

[0071] The potential of VS11 can be selected from a range of -5 V to +5 V. In one embodiment, the potential of VS11 must be selected from a range of, for example, from -2 V to +2 V. In addition, the potential of VS12 can be selected from a range of -5 V to +5 V, and in one embodiment, the potential of VS12 should be selected from a range of, for example, from -2 V to +2 V. The difference between the potential of VS11 and the potential of VS12 should be 0 V. The circuit may be designed to satisfy the expressions VF1 <VS11 and VS12 <VF2 within the ranges of reference potentials described above VF1 and VF2 and within the above potential ranges VS11 and VS12.

[0072] In the example illustrated in FIG. 3, the transfer section 304 and the capacitor section 308 are connected to the photoelectric conversion section 301 in a manner similar to the transfer section 303 and the capacitor section 307. Thus, a set of the transfer section 303 and the capacitor section 307 and a set of the transfer section 304 and the capacitor section 308 are connected in parallel with the plot 301 photovoltaic conversion. Similarly, the transfer section 305 and the capacitor section 309 are connected to the photoelectric conversion section 302 in a manner similar to the transfer section 306 and the capacitor section 310. Thus, a set of the transfer section 306 and the capacitor section 310 and a set of the transfer section 305 and the capacitor section 309 are connected parallel to the photoelectric conversion section 302. The transfer section 304 and the capacitor section 308 may have a configuration similar to the transfer section 303 and the capacitor section 307. The transfer section 305 and the capacitor section 309 may have a configuration similar to the transfer section 306 and the capacitor section 310.

[0073] In this example, gate electrodes that have a MIS gate structure and which are respectively included in the transfer sections 304 and 305 are connected together with the transfer unit 219. The transfer unit 219 is connected to the transfer signal output portion 429. The transfer signal TX2 is supplied from the transfer signal output portion 429 to the transfer unit 219. Sites 304 and 305 transfer have different types of conductivity and are provided in a complementary manner. Thus, the transfer portion 305 is in the off state (non-conductive state) at a time when the transfer portion 304 is in the on state (conductive state) in response to the transfer signal TX2, and the transfer portion 305 is in the on state at a time when the transfer portion 304 is in an off state in response to the transfer signal TX2. The threshold can be set so that both portions 304 and 305 of the transfer were brought to the off state when the node 219 transfer has a predetermined potential. Such a predetermined potential is determined in accordance with the potential in the semiconductor region in the MIS gate structure and the threshold of the MIS gate structure. The difference between the high potential that causes the transfer section 304 to be on and the average potential that makes the transfer section 304 off is 1-5 V. The difference between the low potential that causes the transfer section 305 to be in the on state, and the average potential level that causes the transfer portion 305 to be in the off state is, for example, 1-5 V. A high potential level can be set to potential (positive potential), which is higher than zero potential (0 V), and a low level of potential can be set equal to potential (negative potential), which is lower than zero potential. For example, the average potential level can be set equal to zero potential. Both high and low potential levels can be set equal to the positive potential, or both high and low potential levels can be set equal to the negative potential to reduce the scale of the circuit. The transfer sections 304 and 305 may be connected to separate the transfer nodes, and the on / off state of the transfer sections 304 and 305 can be controlled by using transfer signals independent of each other. The transfer sections 303 and 304 connected to the photoelectric conversion section 301 can be controlled so that the on and off states are opposite relative to each other, that is, are complementary. More specifically, while the transfer portion 303 is in an on state in response to the transfer signal TX1, the transfer portion 304 is in an off state in response to the transfer signal TX2. While the transfer portion 303 is in the off state in response to the transfer signal TX1, the transfer portion 304 is in the on state in response to the transfer signal TX2. In addition, the transfer sections 305 and 306 connected to the photoelectric conversion section 302 can be controlled so that the on and off states are opposite relative to each other, that is, are complementary. More specifically, while the transfer portion 306 is on in response to the transfer signal TX1, the transfer portion 305 is in the off state in response to the transfer signal TX2. While the transfer section 306 is in the off state in response to the transfer signal TX1, the transfer section 305 is in the on state in response to the transfer signal TX2. Accordingly, a signal charge from a single photoelectric conversion section can be alternately transferred by two transfer sections connected to a single photoelectric conversion section.

[0074] The capacitor section 308 induces the collection of electrons transferred from the photoelectric conversion section 301 through the transfer section 304 in the collection section 208. The capacitor section 309 prompts to collect holes transferred from the photoelectric conversion section 302 through the transfer section 305, in the collection section 209. Each of the capacitor sections 308 and 309 has a pn junction diode structure. Node 208 collecting capacitor section 308 is an n-type semiconductor region, and node 209 collecting capacitor section 309 is a p-type semiconductor region. The reference node 228 of the capacitor section 308 is a p-type semiconductor region, and the reference node 229 of the capacitor section 309 is an n-type semiconductor region. The reference node 228 is connected to the reference potential supply portion 411, and the reference potential VF1 is supplied to it. The reference node 229 is connected to the reference potential supply portion 412, and the reference potential VF2 is supplied to it.

[0075] the collection Nodes 208 and 209 are connected together with the reset potential supply portion 414 via the MOS transistor 314 (reset transistor). The reset potential supply portion 414 provides a reset potential VS2. The reset signal RS2 outputted from the reset signal output portion 424 causes the reset transistor 314 to be on. Accordingly, the potentials in the reset nodes 208 and 209 can be set equal to the predetermined reset potentials.

[0076] In the example illustrated in FIG. 3, the charge transferred from the photoelectric conversion sections to the collection units 208 and 209 in the capacitor sections 308 and 309 is discharged. However, similar to the signal conditioning section 315, the signal conditioning section can be connected to the capacitor sections 308 and 309, and a signal based on the charge in the capacitor sections 308 and 309 can be read. If this configuration is used, the signal generated by the signal conditioning section can be combined. based on the charge in the capacitor sections 308 and 309, and a signal generated by the signal generation portion on the basis of the charge in the capacitor sections 307 and 310. Accordingly, the intensity of the pixel signal la can be increased.

[0077] Examples of potentials used in the above scheme will be described. The zero potential (GND) is 0 V. In the first example, VS1, VS2 = 0 V, VF1 = -1 V, VF2 = + 1 V, high potential High = + 2 V, medium potential Mid = 0 V, and low potential level Low = -2 V. In the second example, VS1, VS2 = + 1 V, VF1 = 0 V, VF2 = + 2 V, high potential level High = + 3 V, medium potential level Mid = + 1 V, and low potential level Low = -1 V. The second example is obtained by mixing the individual potentials in the first example on S (V) and corresponds to the case? where S = -1. In the third example, VS1, VS2 = 0 V, VF1 = -2 V, VF2 = + 2 V, high potential level High = + 4 V, medium potential level Mid = 0 V, and low potential level Low = -4 V. The third example is an example in which the potentials in the first example are multiplied by T and corresponds to the case where T = 2. The S value described above can be a positive or negative value, and the T value described above can be less than 1. The second and third examples can be combined, that is, the first example can be shifted by S (B) and multiplied by T. Actual potential values can be properly adjusted while maintaining the relationship among the potential values, the potential differences and the ratio among the potential differences that are obtained from the individual potentials in the above three examples.

[0078] Next, an operation in one Tdr control period of one photoelectric conversion cell 111 of the ranging device 1 will be described with reference to FIG. 4A-4C. In the description below with reference to FIG. 4A-4C, periods from p1 to p10 correspond to a period from time t0 to t10.

[0079] FIG. 4A illustrate the light emission level Le of the light emitting device 21 and the light reception levels Lr1 and Lr2 of the photoelectric conversion device 11. The light emitting device 21 is off in periods p1, p4, p5, p7 and p9 when the light emission level Le corresponds to the amount of light Loff. The light emitting device 21 is in the on state during periods p2, p3, p6 and p8 when the light emission level Le corresponds to the amount of light Lon. Thus, the light emitting device 21 repeats flashes in one cycle, which corresponds to a period Tcy from time t1 to time t5. It is assumed that the flashes are repeated three times to simplify the description. However, in fact, flashes are repeated 100-10000 times during the Tac accumulation period each time a range measurement is performed, and thus sufficient accuracy can be ensured.

[0080] When the speed of light is represented as c (m / s), the delay time from light emission to light reception based on the distance d (m) from the distance measuring device 1 to the target 9 is 2 × d / c (s). The delay time from light emission to light reception can be detected within a single Tcy cycle. The speed of light is 3 × 10 ⁸ m / s, i.e., 0.3 m / ns. Thus, one Tcy cycle is set to, for example, from 1 ns to 1,000 ns, and in one embodiment, one Tcy cycle is set to from 10 ns to 100 ns. For example, the delay from light emission to light reception, corresponding to a distance difference of 0.3 m, is 2 ns. Thus, if one Tcy cycle is 10 ns, a distance difference of 0.3 m can be detected by detecting a physical quantity corresponding to a delay time within 10 ns. In accordance with the Tcy cycle and the number of repeating flashes, one range measurement operation is performed in a short time, ranging from 1 μs to 10 ms. Thus, approximately 10-1000 rows of an array of 110 cells, that is, approximately 1-1000 frames can be read in one second. For example, if the Tdr control period for one line is 1 μs, 1000 frames in 1000 lines can be read in one second. If the Tdr control period for one line is 10 ms, 1 frame in 100 lines can be read in one second.

[0081] The amount of light received by the photoelectric conversion device 11 in response to light emission by the light emitting device 21 is represented as Lra and Lrb. The waveform represented by the light reception level Lr1 indicates that the reception of light started at time t2, which is the time when the period Tda has passed since time t1, when the light emission was started, and that the reception of light is finished at time t4, which is the time, when the period Tda has elapsed from the time t3 when the light emission has been completed, in accordance with the distance from the distance measuring device 1 to the target. The waveform represented by the light reception level Lr2 indicates that the reception of light started at time t2 ′, which is the time when the period Tdb has passed from time t1 when light emission was started, and that the reception of light is completed at time t4 ′, which is the time when the period Tdb has passed from the time t3 when the light emission has been completed, in accordance with the distance from the distance measuring device 1 to the target. In this example, Tda <Tdb, and thus it can be implied that the target that reflected the signal light represented by the light reception level Lr1 is closer to the range measuring device 1 than the target that reflected the signal light represented by the light reception level Lr2 . Furthermore, in this example, Lrb <Lra, and thus, it can be assumed that the signal light represented by the light reception level Lr1 probably has a higher reflection coefficient than the signal light represented by the light reception level Lr2.

[0082] At a time when the photoelectric conversion device 11 receives the light emitted by the light emitting device 21, the amount of light Lra and Lrb received by the photoelectric conversion device 11 includes not only the signal light 82, but also the ambient light 83 illustrated in FIG. . 1A. The amount of ambient light received is represented as Lam. For the amount of light Lra and Lrb, the amount of light obtained by subtracting Lam from it corresponds to a signal light having actual distance information.

[0083] FIG. 4B illustrates the time variation of the reset signals RS1 and RS2 (dashed line), the select signal SL (solid line), the transfer signal TX1 (dash-dot line with one dot) and the transfer signal TX2 (dash-dot line with two dots). A high level of potential is higher than a low level of potential, and an average level of potential is between a high level of potential and a low level of potential. Each of a high level of potential, an average level of potential, and a low level of potential may include potentials in a certain range. For example, the average level of potential is a potential in a certain range including zero potential (0 V). In FIG. 4B, the potential at the position of the horizontal axis representing time corresponds to the average level of the potential. With respect to FIG. 4B, a description will be given for convenience on the assumption that the transistors operate similarly to the case in which the potential level is high at a transient potential between an average potential level and a high potential level (with increasing or decreasing potential). In addition, a description will be given on the assumption that the transistors operate similarly to the case in which the potential level is low with a transition potential between the average potential level and a low potential level (with increasing or decreasing potential). The potential levels that cause individual transistors to turn on and off are not necessarily the same and may differ from each other.

[0084] The reset signals RS1 and RS2 are at a high potential level in the same period, but the periods when the reset signals RS1 and RS2 are at a high potential level may differ from each other. TX1 and TX2 carry signals typically represent a square wave or sine wave with the same cycle in which the positive and negative signs are opposite. The cycles of the transfer signals TX1 and TX2 are identical to the cycle Tcy, in which the light emitting device 21 emits light. However, the cycles of the transfer signals may differ slightly from the cycle of light emission if a decrease in the accuracy of range measurement is allowed.

[0085] In the period p1, when the reset signals RS1 and RS2 have a potential higher than the average potential level (usually a high potential level), the reset transistors 313 and 314 are on. From time t1 to time t10, which is the period when the reset signals RS1 and RS2 have an average potential level, the reset transistors 313 and 314 are in an off state. In FIG. 4A, an example is given under the assumption that the reset signals RS1 and RS2 are the same. Alternatively, the reset signals RS1 and RS2 may differ from each other in a period that is not illustrated.

[0086] In periods p2, p3, p6 and p8, when the transfer signal TX1 has a potential higher than the average potential level (usually a high potential level), the transfer section 303 is in the on state, while the transfer section 306 is in the off state. In periods p4, p5, p7 and p9, when the transfer signal TX1 has a potential lower than the average potential level (usually a low potential level), the transfer section 303 is in the off state, while the transfer section 306 is in the on state. The period from the moment when the reset transistors 313 and 314 change the on state to the off state, until the moment when one of the transfer sections 303 and 306 changes the state to the on state, can be as short as possible.

[0087] In periods p2, p3, p6 and p8, when the TX2 transfer signal has a potential lower than the average potential level (usually a low potential level), the transfer section 305 is on, while the transfer section 304 is off. In periods p4, p5, p7 and p9, when the TX2 transfer signal has a potential higher than the average potential level (usually a high potential level), the transfer section 305 is in the off state, while the transfer section 304 is in the on state. The period from the moment when the reset transistors 313 and 314 change the on state to the off state until the moment when one of the transfer sections 304 and 305 changes the state to the on state can be as short as possible.

[0088] During the period (or during) when the transfer signal TX1 has an average potential level, the transfer sections 303 and 306 are in the off state. During the period (or during) when the transfer signal TX2 has an average potential level, the transfer sections 304 and 305 are in the off state. The average potential level is determined in accordance with the characteristics of the transfer sections 303, 304, 305 and 306, as described above.

[0089] FIG. 4C illustrates a potential change in the detection unit 220. A change in potential S1 represents a change in potential in accordance with the light reception level Lr1, and a change in potential S2 represents a change in potential in accordance with the light reception level Lr2.

[0090] During the period p1, the potentials in the collection nodes 207 and 210 and in the detection section 220 are set equal to the potentials corresponding to the reset potential VS1 (potentials VS11 and VS12) by the reset potential supply portion 413.

[0091] In the period p2, the electrons generated by the photoelectric conversion section 301 in accordance with the amount of light Lam of the ambient light 83 are transferred to the capacitor section 307. When the electrons are formed by the photoelectric conversion section 301, the potential at the cathode 201 becomes higher than the potential at the anode 211. If the potential at the anode 211 is, for example, VF1 = −2 V, the potential at the cathode 201 is approximately −1 V. The discharge potential VS1 makes the potential at the collecting unit 207 higher than the potential at the anode 211 (VF1 <VS1). Thus, when the transfer portion 303 is on, the electrons that have been formed quickly move to the collecting portion 207, in which the potential is higher than on the cathode 201. According to the electron transfer, the potential in the detection portion 220 connected to the portion 207 collection decreases.

[0092] In the period p3, the electrons generated by the photoelectric conversion section 301 in accordance with the amount of light Lra including the signal light 82, which is larger than the amount Lam of ambient light 83, is transferred to the capacitor section 307. According to the electron transfer, the potential in the detection unit 220 connected to the collection unit 207 decreases with a gradient more than in the period p2. This is because the amount of received light per unit time increases by the amount of signal light 82.

[0093] In the period p4, the holes formed by the photoelectric conversion section 302 in accordance with the amount of light Lra including the signal light 82, which is larger than the amount Lam of ambient light 83, is transferred to the capacitor section 310. According to the hole transfer, the potential in the detection unit 220 connected to the collection unit 210 increases.

[0094] In periods p2 and p3, the transfer portion 305 is in an on state. Thus, the holes formed by the photoelectric conversion section 302 in periods p2 and p3 are transferred to the capacitor section 309 in periods p2 and p3. Thus, among the holes transferred to the capacitor section 310, after the transfer section 306 is turned on at time t3, for example, in the period p4, the number of holes formed by the photoelectric conversion section 302 in the period p4 is greater than the number of holes formed in the section 302 photovoltaic conversion in periods p2 and p3. Ideally, holes formed by the photoelectric conversion section 302 in periods p2 and p3 are not transferred to the capacitor section 310 in the period p4.

[0095] In the period p5, the holes formed by the photoelectric conversion section 302 in accordance with the ambient light quantity Lam 83 are transferred to the capacitor section 310. In accordance with the transfer of the potential holes in the detection section 220 connected to the collecting section 210, increases.

[0096] The same operation is repeated in periods p6, p7, p8 and p9. In periods p4 and p5, the transfer portion 304 is in an on state. Thus, the electrons formed by the photoelectric conversion section 301 in periods p4 and p5 are transferred to the capacitor section 308 in periods p4 and p5. Thus, among the electrons transferred to the capacitor section 307, after the transfer section 303 is turned on at time t5, for example, in the period p6, the number of electrons generated by the photoelectric conversion section 301 in the period p6 is greater than the number of electrons formed by the section 301 photovoltaic conversion in periods p4 and p5. Ideally, the electrons formed by the photoelectric conversion section 301 in periods p4 and p5 are not transferred to the capacitor section 307 in period p6.

[0097] By using such a Tcy loop repeated several times, a signal suitable for measuring a range can be obtained from which the ambient light component 83 has been removed and into which the signal light component 82 has been included.

[0098] Regarding the light reception level Lr1, the delay time Tda is less than a quarter of the cycle Tcy (Tda <Tcy / 4). Thus, electrons transferred during the period p3 effectively dominate in the potential in the detection unit 220, and the potential in the detection unit 220 becomes lower than the reset potential VS1 (the absolute value increases). If the delay time Tdb is a quarter of the Tcy cycle, as in the light reception level Lr2 (Tdb = Tcy / 4), the number of electrons and the number of holes transferred to the collection nodes 207 and 210 within the same Tcy cycle are equal to each other, and thus , the potential at the detection unit 220 is equal to the reset potential VS1. If the delay time Tda> Tcy / 4, the holes transferred during the period p4 effectively prevail in the potential in the detection unit 220, and the potential in the detection node 220 becomes higher than the reset potential VS1 (the absolute value increases).

[0099] In this case, the on period and the off period of the light emitting device 21 in one cycle Tcy are equal to each other, but the on period and the off period may be different from each other. If the on period and the off period are different from each other, the output signal from the signal generating portion 315 can be adjusted based on the difference between the on period and the off period. In addition, although the on-period and the shutter-off period of the transfer shutter in the same Tcy cycle here are equal to each other, the on-period and the off-period may be different from each other. If the on period and the off period are different from each other, the output signal from the signal generating portion 315 can be adjusted based on the difference between the on period and the off period.

[00100] A potential that appears in the detection unit 220 will be quantified. Among the electrons serving as the signal charge, the component obtained from the ambient light 83 is represented as (-N), and the component obtained from the signal light 82 is represented as (-S). Among the holes serving as a signal charge, a component obtained from ambient light 83 is represented as (+ N), and a component obtained from signal light 82 is represented as (+ S). A coefficient proportional to the duration of the period p2 is represented as a, a coefficient proportional to the duration of the period p3 is presented as b, a coefficient proportional to the duration of the period p4 is presented as c, and a coefficient proportional to the duration of the period p5 is presented as d.

[00101] First, under the assumption that the recombination of electrons and holes does not occur in the detection unit 220, the charge quantities in the collection nodes 207 and 210 are calculated. The increase in the amount of charge in the collection unit 207 during the period p2 is expressed as a × (-N), and the amount of charge in the collection unit 207 during the time t2 is expressed as a × (-N). On the other hand, the increase in the amount of charge in the collection unit 210 in the period p2 is 0, and the amount of charge in the collection unit 210 during t2 is 0. The increase in the amount of charge in the collection unit 207 in the period p3 is expressed as b × (−NS), and the amount of charge in the collection node 207 at time t3 is expressed as a × (-N) + b × (-NS). On the other hand, the increase in the amount of charge in the collection unit 210 in the period p3 is 0, and the amount of charge in the collection unit 210 during t3 is 0. The increase in the amount of charge in the collection unit 207 in the period p4 is 0, and the amount of charge in the collection unit 207 at time t4 expressed as a × (-N) + b × (-NS). The increase in the amount of charge in the collection unit 210 during the period p4 is expressed as c × (+ N + S), and the amount of charge in the collection unit 210 during p4 is expressed as c × (+ N + S). The increase in the amount of charge in the collection unit 207 during the period p5 is 0, and the amount of charge in the collection unit 207 during t5 is expressed as a × (-N) + b × (-N-S). On the other hand, an increase in the amount of charge in the collection unit 210 during the period p5 is expressed as d × (+ N), and the amount of charge in the collection unit 210 during the time t5 is expressed as c × (+ N + S) + d × (+ N) .

[00102] The actual amount of charge in the detection unit 220 at time t5 corresponds to the amount of charge obtained by subtracting electrons and holes, which is expressed by the following expression: a × (-N) + b × (-NS) + c × (+ N + S ) + d × (+ N) = (a + b) × (-N) + (c + d) × (+ N) + b × (-S) + c × (+ S) = ((c + d ) - (a + b)) × N + (cb) × S. Between time t1 and time t5, if the ambient light 83 is constant, and if the periods when the transfer portions 303 and 306 are complementary in the on state are the same, the expression (c + d) - (a + b) = 0 is satisfied . Thus, it is understood that the potential that appears at the detection unit 220 at time t5 is obtained as a signal that is (cb) × S, from which at least a portion of the ambient light component 83 has been removed, and which indicates only the signal light component 82.

[00103] Figs. 5A-5D show an illustrative arrangement of components of a photoelectric conversion cell 111. FIG. 5A is a schematic top view of a photoelectric conversion cell 111. FIG. 5B is a schematic cross section taken along line VB-VB in FIG. 5A, FIG. 5C is a schematic cross section taken along line VC-VC in FIG. 5A, and FIG. 5D is a schematic cross section along the line VD-VD in FIG. 5 A.

[00104] The semiconductor substrate 100 is provided with a p-type semiconductor region 511 serving as a p-type pocket, and an n-type semiconductor region 512 serving as an n-type pocket. For example, n-type semiconductor region 512 is an n-type epitaxial layer, while p-type semiconductor region 511 is a p-type impurity diffusion region formed by ion doping with an p-type impurity of an n-type epitaxial layer. Many plots comprising one semiconductor region, that is, each of the semiconductor regions 511 and 512, have the same type of conductivity and are continuous with respect to each other. At the same time, many sections are areas whose positions in at least any of the directions X, Y and Z differ. The plurality of regions constituting each of the semiconductor regions 511 and 512 may have different impurity concentrations. For example, the p-type semiconductor region 511 may have an impurity concentration that deviates in the depth direction (Z direction) of the semiconductor substrate 100.

[00105] In the photoelectric conversion cell 111, the photoelectric conversion section 301 and the photoelectric conversion section 302 are arranged along the front surface 1000 of the semiconductor substrate 100. The direction in which the photoelectric conversion sections 301 and 302 are located is the X direction, the direction parallel to the front surface 1000 and vertical with respect to the X direction, is the Y direction, and the direction vertical with respect to the front surface 1000 is the Z direction.

[00106] As a structure different from that illustrated in FIG. 5A-5D, the photoelectric conversion sections 301 and 302 can be arranged in the Z direction. Thus, one of the photoelectric conversion sections 301 and 302 can be positioned deeper in the semiconductor substrate 100 than the other. For example, the cathode (n-type semiconductor region) of the photoelectric conversion section 301 and the anode (p-type semiconductor region) of the photoelectric conversion section 302 are located in the Z direction from the front surface 1000. In addition, the anode (p-type semiconductor region) of the photoelectric section 301 the transformations and the cathode (n-type semiconductor region) of the photoelectric conversion section 302 are disposed between them to achieve pn junction isolation. Using a p-type semiconductor region serving as a charge transfer path that is connected to the anode of the photoelectric conversion section 302 extending toward the front surface 1000, the signal charge of the photoelectric conversion section 302 located in a deep position can be collected via the movement path charge. However, in this case, the amount of light subjected to photoelectric conversion by the photoelectric conversion section in a finer position is different from the amount of light subjected to photoelectric conversion by the photoelectric conversion section in a deeper position, and accordingly there is a large difference in the amount of signal charge that will be formed. This is because light is absorbed by the semiconductor substrate 100 and attenuated. Thus, in order to reduce the difference in the amount of received light between the photoelectric conversion sections 301 and 302, the photoelectric conversion sections 301 and 302 can be arranged along the front surface 1000 of the semiconductor substrate 100.

[00107] In FIG. 5A-5D, thick lines represent local connecting lines provided in the photoelectric conversion cell 111. The circles represent the positions of the contact areas that are used to establish the connection between the semiconductor substrate 100 and the local connecting lines or global connecting lines (not illustrated), such as connecting lines 120 rows and connecting lines 130 columns described above with reference to FIG. 1B. In a typical contact region, the contact jumper and the semiconductor substrate 100 are connected to each other. Here, the local connecting line is a connecting line for electrically connecting the elements in the photoelectric conversion cell 111 to each other. On the other hand, the global connecting line is a connecting line for connecting the cells 111 of the photoelectric conversion with each other or connecting the cells 111 of the photoelectric conversion with a circuit outside the array 110 cells. Column connecting lines 120 and column connecting lines 130 described above with reference to FIG. 1B are typical global trunks. A connecting line is an element made up of a conductor to establish an electrical connection. In the contact portion for establishing a connection with the semiconductor region, a portion of the semiconductor region connected to the conductor, such as a contact jumper, is a region with a high concentration of impurity compared to the other part, and thus a favorable electrical connection can be provided.

[00108] As illustrated in FIG. 5B, in the Y direction, the n-type semiconductor region 507, the transfer gate electrode 503, the n-type semiconductor region 501, the transfer gate electrode 504, and the n-type semiconductor region 508 are arranged in this order along the line VB-VB.

[00109] As illustrated in FIG. 5C, in the Y direction, the p-type semiconductor region 510, the transfer gate electrode 505, the p-type semiconductor region 502, the transfer gate electrode 506, and the p-type semiconductor region 509 are arranged in this order along the VC-VC line.

[00110] As illustrated in FIG. 5A, in the X direction, the gate electrode 513 of the reset transistor 313, the gate electrode 514 of the reset transistor 314, the gate electrode 515 of the gain transistor and the gate electrode 516 of the select transistor 316 are arranged in this order. The gate electrode 515 of the gain transistor forming the signal generating portion 315 serves as an input node of the signal shaping portion 315 and is connected to the detection portion 220 directly or through an electric low-pass filter 433.

[00111] The n-type semiconductor region 507 is part of the capacitor section 307 and constitutes a collection unit 207. In other words, the n-type semiconductor region 507 is the first floating diffusion region. The semiconductor region 511 forms a pn junction together with the semiconductor region 507, and the semiconductor region 511 constitutes the reference assembly 217 of the capacitor section 307.

[00112] The p-type semiconductor region 510 is part of the capacitor section 310 and constitutes a collection unit 210. In other words, the p-type semiconductor region 510 is the second floating diffusion region. The semiconductor region 512 forms a pn junction together with the semiconductor region 510, and the semiconductor region 512 constitutes the reference assembly 200 of the capacitor section 310.

[00113] The n-type semiconductor region 501 is part of the photoelectric conversion section 301 and constitutes the photodiode cathode 201. The semiconductor region 501 forms a pn junction together with the semiconductor region 511, and the semiconductor region 511 constitutes the anode 211 of the photodiode. The concentration of the impurity of the n-type semiconductor region 501 can be quite low, and it can be depleted at the contact potential difference. Accordingly, in the electron-hole pairs formed by the photoelectric conversion section 301, electrons formed as a signal charge will be less likely to accumulate in the photoelectric conversion section 301. As a result, the electron transfer efficiency from the photoelectric conversion section 301 to the semiconductor region 507 is increased. In addition, electrons formed on the basis of light can be completely transferred to the semiconductor region 507, and noise caused by low transfer efficiency can be reduced. Holes not used as a signal charge in the photoelectric conversion section 301 are discharged through the p-type semiconductor region 511. A front surface region, which is a p-type semiconductor region, is provided between the n-type semiconductor region 501 and the front surface 1000 of the semiconductor substrate 100, and the n-type semiconductor region 501 is located away from the front surface 1000. Accordingly, the photoelectric section 301 conversion serves as a photodiode with in-depth transition. In FIG. 5A-5D, a p-type semiconductor region serving as a front surface region is integrated with a p-type semiconductor region 511.

[00114] The p-type semiconductor region 502 is part of the photoelectric conversion section 302 and constitutes the anode 202 of the photodiode. The semiconductor region 502 forms a pn junction together with the semiconductor region 512, and the semiconductor region 512 constitutes the photodiode cathode 212. The impurity concentration of the p-type semiconductor region 502 can be quite low, and it can be depleted at the contact potential difference. Accordingly, in electron-hole pairs formed by the photoelectric conversion section 302, holes formed as a signal charge will be less likely to accumulate in the photoelectric conversion section 302. As a result, the efficiency of hole transfer from the photoelectric conversion section 302 to the semiconductor region 510 increases. In addition, holes formed on the basis of light can be completely transferred to the semiconductor region 510, and noise caused by low transfer efficiency can be reduced. Electrons not used as a signal charge in the photoelectric conversion section 302 are discharged through a p-type semiconductor region 511. A front surface region, which is an n-type semiconductor region, is provided between the p-type semiconductor region 502 and the front surface 1000 of the semiconductor substrate 100, and the p-type semiconductor region 502 is located away from the front surface 1000. Accordingly, the photoelectric section 302 conversion serves as a photodiode with in-depth transition. In FIG. 5A-5D, an n-type semiconductor region serving as a front surface region is integrated with an n-type semiconductor region 512.

[00115] The n-type semiconductor region 508 forms a p-n junction together with the semiconductor region 511. The semiconductor region 508 is part of the capacitor section 308 and constitutes the collection node 208. The p-type semiconductor region 509 forms a p-n junction together with the semiconductor region 512. The semiconductor region 509 is part of the capacitor section 309 and constitutes the collection unit 209. The n-type semiconductor region 501 and the p-type semiconductor region 502 are arranged in the X direction along the front surface 1000. The n-type semiconductor region 501 and the p-type semiconductor region 502 are isolated from each other, but can be in contact with each other. In this example, the p-type semiconductor region 511 and the n-type semiconductor region 512 form a pn junction between the n-type semiconductor region 501 and the p-type semiconductor region 502. Accordingly, the semiconductor region 501 and the semiconductor region 502 are electrically isolated from each other (pn junction isolation).

[00116] The reference potential VF1 is supplied to the semiconductor region 511 from the contact jumper 611, which constitutes the reference potential supply portion 411. In addition, the reference potential VF2 is supplied to the semiconductor region 512 from the contact jumper 612, which constitutes the reference potential supply portion 412. The reference potential VF1 is lower than the reference potential VF2, and thus a reverse bias voltage is applied between the semiconductor regions 511 and 512. Thus, the depletion layer formed between the semiconductor regions 511 and 512 makes the semiconductor regions 511 and 512 electrically isolated from each other. Accordingly, the electrons formed by the n-type semiconductor region 501 and the holes formed by the p-type semiconductor region 502 can be electrically isolated from each other. In this way, the charge can be collected by the appropriate collection unit at suitable timing, and the signal charges for ranging can be selectively recombined. In addition, the photoelectric conversion sections 301 and 302 are isolated from each other by isolation of the pn junction, and thus the interval between the photoelectric conversion sections 301 and 302 can be reduced (for example, less than 1 μm). Accordingly, the difference in the amount of received light between the photoelectric conversion sections 301 and 302 can be reduced. In addition, isolation of the pn junction can suppress the occurrence of dark current compared to insulation of the insulator.

[00117] In the array of 110 cells, each of the photoelectric conversion cells 111 having the structure illustrated in FIG. 5A is placed in the matrix. Among the plurality of photovoltaic cells 111, an n-type semiconductor region 512 is provided, serving as a continuous common pocket. On the other hand, among the plurality of photovoltaic cells 111, a p-type semiconductor region 511 is provided, serving as a discontinuous insulating pocket. Thus, the p-type semiconductor region 511 of a certain photoelectric conversion cell 111 can be electrically isolated from the p-type semiconductor region 511 of at least one of the adjacent photoelectric conversion cells 111 by isolation, such as p-junction isolation. In contrast to the example described above, an n-type semiconductor region 512 can serve as an insulating pocket, and a p-type semiconductor region 511 can serve as a common pocket. Thus, using one region from the n-type semiconductor region 512 and the p-type semiconductor region 511 511 as a common pocket, the configuration of the photoelectric conversion cell 111 can be simplified.

[00118] In a plan view, the transfer gate electrode 503, which includes at least a portion located between the n-type semiconductor region 501 and the n-type semiconductor region 507, constitutes the transfer portion 303. In this example, the transfer gate electrode 503 is located above part of the semiconductor region 501 and part of the semiconductor region 507. In a plan view, the transfer gate electrode 504 that includes at least a portion located between the n-type semiconductor region 501 and the n- semiconductor region 508 of the type constitutes a transfer portion 304. In this example, the transfer gate electrode 504 is located above part of the semiconductor region 501 and part of the semiconductor region 508.

[00119] In a plan view, the transfer gate electrode 505, which includes at least a portion located between the p-type semiconductor region 502 and the p-type semiconductor region 510, constitutes the transfer portion 306. In this example, the transfer gate electrode 505 is located above part of the semiconductor region 502 and part of the semiconductor region 510. In a plan view, the transfer gate electrode 506, which includes at least a portion located between the p-type semiconductor region 502 and the p- semiconductor region 509 type constitutes a transfer portion 305. In this example, the transfer gate electrode 506 is located above part of the semiconductor region 502 and part of the semiconductor region 509.

[00120] An insulating film 500 is provided between the semiconductor substrate 100 and the transfer gate electrodes 503, 504, 505 and 506. The insulating film 500 functions as an insulating film of the shutter.

[00121] The local connection line 618 is connected to the transfer gate electrodes 503 and 505 through the contact jumpers 603 and 605 so that the same transfer signal TX1 is supplied to the transfer gate electrodes 503 and 505. Here, the transfer gate electrodes 503 and 505 are provided as separate gate electrodes. The gate electrode performs a charge / discharge each time it is actuated, and thereby the current corresponding to the flows of the MOS capacitance flows each time a switching is performed. In the case of high-speed control, the MOS capacitance decreases as the size of the gate electrode of the transistor decreases, and accordingly, small electric currents and power are stored. Thus, with separately provided transfer gate electrodes 503 and 505, the size of the gate electrodes can be reduced as much as possible.

[00122] Alternatively, an integrated gate electrode may be provided, including a portion serving as a transfer portion 303 and a portion serving as a transfer portion 305. Through this configuration, the number of connecting lines can be reduced, the capacitance and resistance of the connection can be reduced, and accordingly, the accuracy of the complementary control of the transfer sections 303 and 305 can be improved. In addition, the reduced number of connecting lines enables a higher aperture ratio and higher sensitivity. The same applies to the transfer gate electrodes 504 and 506.

[00123] A reset transistor including a gate electrode 513 is connected to the semiconductor regions 507 and 510 via contact jumpers 607 and 610, a local connection line 620, and a contact jumper 613. In this example, the local connection line 620 constitutes a detection unit 220. The gate electrode 513 is connected to a reset signal output portion 423 outside the array of cells through a jumper wire, a local trunk and a global trunk. The contact jumper 613 is connected to the semiconductor region 523, which corresponds to one of the source / drain regions of the reset transistor. Other source / drain areas of the reset transistor are connected to the reset potential supply portion 413 outside the array of cells via the global trunk. In addition, a reset transistor including a gate electrode 514 is connected to the semiconductor regions 508 and 509 via a local connecting line and a contact jumper.

[00124] A gain transistor including a gate electrode 515 is connected to the semiconductor regions 507 and 510 through a local connection line 620 and a contact jumper 615. A contact jumper 615 is connected to a gate electrode 515 of a gain transistor. A leakage of the amplification transistor is connected to the power supply portion 432 through a jumper wire and a global trunk. The source of the gain transistor is connected to a leak of a select transistor 316 including a gate electrode 516. The source of the selection transistor 316 is connected to the global connecting line (column connecting lines 130) through a jumper wire.

[00125] The contact jumper 611 is connected to the semiconductor region 511. The contact jumper 611 is connected to the reference potential supply portion 411 outside the array 110 of the cells through a global connecting line. The contact jumper 612 is connected to the semiconductor region 512. The contact jumper 612 is connected to the reference potential supply portion 412 outside the array 110 of cells through a global connecting line. Thus, the reference potential is supplied to the semiconductor regions 511 and 512 through the connecting lines, and thereby changes in the reference potential in the individual photoelectric conversion cells 111 in the array 110 of the cells can be reduced. Alternatively, the reference potential may be supplied without placing contact jumpers 611 and 612 in the photoelectric conversion cells 111. In this case, the impurity diffusion layer extending from the inner part of the array of 110 cells to its outer side can be provided on the semiconductor substrate 100, and a reference potential can be supplied to the impurity diffusion layer outside the array of 110 cells through a connecting line and a contact jumper. However, as described above, when the p-type semiconductor region 511 is an insulated pocket, it is difficult to make the p-type semiconductor region 511 extending beyond the array of 110 cells. Thus, with respect to at least the insulated pocket, the reference potential can be supplied to it through a conductor provided on the semiconductor substrate 100, for example, through a global connecting line, a local connecting line and a contact jumper. The same applies to the case in which the n-type 512 semiconductor region 512 is an insulated pocket.

[00126] The semiconductor regions 507 and 510 are connected to each other via a conductor. In this example, a conductor that connects the semiconductor regions 507 and 510 includes a local connection line 620 and contact jumpers 607 and 610. The conductor that connects the semiconductor regions 507 and 510 is made of a material with a higher conductivity than the semiconductor substrate 100. for example, a metal material, a metal-containing compound, or polycrystalline silicon. Metallic material and a metal-containing compound are used for the connecting lines and contact jumpers, and polycrystalline silicon is used for the gate electrodes. The metal-containing compound may be a semiconductor-metal composite material, such as a silicide. These materials are used alone or in combination to connect the semiconductor regions 507 and 510. Thus, the semiconductor regions 507 and 510 are connected to each other via a conductor, and thereby the semiconductor regions 507 and 510 can be connected to each other without using a pn junction . Typically, semiconductor regions 507 and 510 can be connected to each other via an ohmic contact. With semiconductor regions 507 and 510 connected to each other via a conductor, a configuration is obtained in which the semiconductor regions 507 and 510 do not form a pn junction. Thus, in the case of the recombination of electrons and holes, the time for damping the potential difference between the semiconductor regions 507 and 510 can be reduced. As a result, the output of the detection unit 220 can be stabilized, and a very accurate range measurement can be realized.

[00127] FIG. 6A-6D show illustrative structures for making an electrical connection between semiconductor regions 507 and 510. FIG. 6A-6D correspond to a cross-section including transfer gate electrodes 503 and 505 and the semiconductor regions 507 and 510 illustrated in FIG. 5A. FIG. 6A illustrate a structure for producing an electrical connection between the semiconductor regions 507 and 510 of FIG. 5A-5D. FIG. 6B-6D illustrate shapes other than those in FIG. 6A to obtain an electrical connection between the semiconductor regions 507 and 510. In FIG. 6A-6D, the transfer gate electrodes 503 and 505 are electrically connected to each other via a local connection line 618. The local connection line 618 is in contact with a contact jumper 603 on the transfer gate electrode 503 and a contact jumper 605 on the transfer gate electrode 505. Contact jumpers 603 and 605 extend through the interlayer insulating film 526, and the local connecting line 618 is located on the interlayer insulating film 526. The local connecting line 618 can be, for example, an aluminum connecting line that includes an electrically conductive section, mainly containing aluminum, and a barrier metal portion including a titanium layer and / or a titanium nitride layer. Alternatively, the local connecting line 618 may be a copper connecting line including an electrically conductive portion mainly containing copper and a barrier metal portion including a tantalum layer and / or a tantalum nitride layer. The copper connecting line has a single damascene structure or a double damascene structure. Other local connecting lines are also aluminum connecting lines or copper connecting lines.

[00128] In the form illustrated in FIG. 6A, the semiconductor regions 507 and 510 are connected to each other via contact jumpers 607 and 610 and a local connecting line 620 that connects the contact jumpers 607 and 610. The contact jumper 607 is connected to the semiconductor region 507 through an interlayer insulating film 526, and the contact jumper 610 is connected with the semiconductor region 510 through the interlayer insulating film 526. Each of the contact jumpers 607 and 610 includes an electrically conductive section, mainly containing tungsten, and a section of a barrier metal, which Position the conductive portion and between the interlayer insulating film 526, and which includes a layer of titanium and / or layer of titanium nitride. The local connecting line 620 is an aluminum connecting line including an electrically conductive portion, mainly containing aluminum, and a barrier metal portion that is located between the electrically conductive portion and the interlayer insulating film 526, and which includes a titanium layer and / or a layer from titanium nitride. Alternatively, the local connecting line 620 is a copper connecting line including an electrically conductive portion mainly containing copper and a barrier metal portion that is located between the electrically conductive portion and the interlayer insulating film 526, and which includes a tantalum layer and / or a layer of tantalum nitride.

[00129] In the form illustrated in FIG. 6B, the semiconductor regions 507 and 510 are connected to each other via a contact jumper 623, which is a conductor that is in contact with both semiconductor regions 507 and 510. The contact jumper 623 includes an electrically conductive portion mainly comprising tungsten, and a portion of a barrier metal that is located between the electrically conductive portion and the interlayer insulating film 526, and which includes a layer of titanium and / or a layer of titanium nitride. An insulating film 527, which is separated from the insulating film 500 and the interlayer insulating film 526, is provided between the contact jumper 623 and the semiconductor substrate 100. The insulating film 527 insulates the contact jumper 623 and the p-type semiconductor region 511 from each other and insulates the contact jumper 623 and the semiconductor an n-type region 512 from each other. Accordingly, the electrical connection between the p-type semiconductor region 511 and the n-type semiconductor region 512 can be blocked.

[00130] In the form illustrated in FIG. 6C, the semiconductor regions 507 and 510 are connected to each other via a local junction line 624, which is a conductor that is in contact with both semiconductor regions 507 and 510. The local junction line 624 can be formed by applying a tungsten film or a silicide film. A local junction line 624 is located between the interlayer insulating film 526 and the semiconductor substrate 100. The local junction line 624 can be formed after the transfer gate electrodes 503 and 505 have been formed, and then the interlayer insulating film 526 and the contact jumpers 603 and 605 can be formed. An insulating film 528, which is separated from the insulating film 500 and the interlayer insulating film 526, is provided between the local connection line 624 and the semiconductor substrate 100. The insulating film NCA 528 isolates a local line connector 624 and semiconductor region 511 p-type from one another and isolates the local line connector 624 and semiconductor region 512 n-type from each other. Accordingly, the electrical connection between the p-type semiconductor region 511 and the n-type semiconductor region 512 can be blocked.

[00131] In the form illustrated in FIG. 6D, the semiconductor regions 507 and 510 are connected to each other via a local junction line 625, which is a conductor that is in contact with both semiconductor regions 507 and 510. The local junction line 625 can be formed by applying a polycrystalline silicon film and can be formed at the same time as the transfer gate electrodes 503 and 505. A local junction line 625 is located between the interlayer insulating film 526 and the semiconductor substrate 100. An insulating film 500 is located between the local junction line 625 and the semiconductor substrate 100 to achieve isolation between the local junction line 625 and the p-type semiconductor region 511 and isolation between the local junction line 625 and an n-type semiconductor region 512.

[00132] The above-described local connecting lines and global connecting lines can be formed by joining a plurality of connecting layers superposed on each other in a direction vertical to the front surface 1000 of the semiconductor substrate 100 by using through jumpers.

[00133] Next, with reference to FIG. 7, a description will be given of an example modification of the equivalent circuit of the photoelectric conversion cell 111 described above with reference to FIG. 3.

[00134] The node 207 for collecting the capacitor section 307 is connected to the node 220 detection through the transistor 318 switching. When the switching signal SW1 outputted from the switching signal output portion 438 causes the switching transistor 318 to be on, a potential corresponding to the potential in the collecting portion 207 appears in the detecting portion 220. The node 210 to collect the capacitor section 310 is connected to the node 220 detection through the transistor 319 switching. When the switching signal SW2 outputted from the switching signal output portion 439 causes the switching transistor 319 to be on, a potential corresponding to the potential in the collecting section 210 appears in the detection section 220. Thus, the on / off state of the electrical connection to the collection nodes 207 and 210 can be switched in this modification example. In other words, the collection nodes 207 and 210 are electrically connected to each other via switching transistors 318 and 319. Alternatively, one of the switching transistors 318 and 319 may be omitted.

[00135] The reset potential supply portion 413 is connected to the collection portion 207 of the capacitor portion 307 via the reset transistor 313. The reset signal RS1 outputted from the reset signal output portion 423 causes the reset transistor 313 to be on. Accordingly, the reset potential VS1 is supplied from the reset potential supply portion 413 to the collection portion 207 of the capacitor section 307. The reset potential supply portion 417 is connected to the collection portion 210 of the capacitor section 310 via the reset transistor 317. The reset signal RS3 outputted from the reset signal output portion 427 causes the reset transistor 317 to be on. Accordingly, the reset potential VS3 is supplied from the reset potential supply portion 417 to the collection portion 210 of the capacitor section 310.

[00136] In one embodiment, the potential difference between the reset potential of VS1 and the reset potential of VS3 should be less than 0.10 V, and the potential difference between the reset potential of VS1 and the reset potential of VS3 should be 0 V. However, a small potential difference of less than 0 is allowed. 10 V due to inevitable resistance or manufacturing error. The reset potential VS1 and the reset potential VS3 can be the potential between the reference potential VF1 and the reference potential VF2. For example, the reset potential VS1 may be higher than the reference potential VF1 (VF1 <VS1). In addition, the reset potential of VS3 may be lower than the reference potential of VF2 (VS3 <VF2). The reset potential of VS1, for example, is from -1 V to +1 V. In one embodiment, the reset potential of VS1 is from -0.5 V to +0.5 V. The reset potential of VS1, for example, is from -1 V to + 1 V and in one embodiment is from -0.5 V to +0.5 V.

[00137] With the reset potential VS1 supplied to the capacitor section 307, the electrons held by the capacitor section 307 are discharged to the reset potential supply section 413. With the reset potential VS3 supplied to the capacitor section 310, the holes held by the capacitor section 310 are discharged to the reset potential supply section 417. According to this modification example, one signal from the signal based on the charge (electrons) obtained through the photoelectric conversion performed by the photoelectric conversion section 301 and the signal based on the charge (hole) obtained through the photoelectric conversion performed by the photoelectric conversion section 302 may be selectively read from detection unit 220. With this mode of operation, a photoelectric conversion device 11 capable of performing both image capture and range measurement can be obtained.

[00138] In this modification example, capacitor sections 308 and 309 may be omitted to quickly discharge an unnecessary charge by turning on / off the transfer sections 304 and 305. By this configuration, the aperture ratio and the area of the photoelectric conversion sections can be increased by reducing the number of connecting lines, and the sensitivity can be increased.

[00139] FIG. 8 illustrates an example of the operation of the circuit illustrated in FIG. 7. There is a reading period Tnr in which ambient light 83 is read, and a removal period Tcl in which the ambient light component 83 is removed between the accumulation period Tac and the reading period Tsr illustrated in FIG. 2. During the accumulation period Tac after the reset period Trs, the switching transistor 318 is in an on state and the switch transistor 319 is in an off state. During the reading period Tnr, the selection transistor 316 is in an on state, while the switch transistor 318 remains in an on state, and the switch transistor 319 remains in an off state. Accordingly, a signal is read in the detection unit 220, in which a potential corresponding to the potential in the collection unit 207 appears. After the reading period Tnr, there is a removal period Tcl in which at least part of the ambient light component 83 is removed. During the removal period Tcl, the selection transistor 316 is turned off and the switching transistors 318 and 319 illustrated in FIG. 7 are on. Accordingly, the recombination between the electrons and the holes balances the ambient light component 83. Then, the potential from which the ambient light component 83 has been removed appears in the detection unit 220. During the Tsr reading period, the selection transistor 316 is turned on to read the signal from which the ambient light component 83 has been removed. As a result of reading the ambient light 83 by this method, not only an image including distance information, but also an image can be obtained based on ambient light 83.

[00140] Examples of application of the information processing system SYS will be described with reference to FIG. 1A.

[00141] A first example of application of an information processing system SYS is an example of its application to a camera equipped with an image pickup apparatus. The information processing apparatus 2 controls the range measuring apparatus 1 upon receiving a signal indicating a command to perform a range measurement from the control apparatus 3 including an input unit, for example, a focus control unit (for example, a focus button). Then, the range measuring apparatus 1 provides a signal including distance information representing the distance to the target 9, which is an object, to the information processing apparatus 2. The information processing apparatus 2 processes the signal and generates a control signal for controlling mechanical components such as a lens, aperture, and shutter to establish conditions suitable for capturing the image of the target 9. The information processing apparatus 2 then provides a control signal to the driving apparatus 4, such as a motor, which controls the lens, aperture and shutter. The drive unit 4 drives these mechanical components in response to a control signal. Upon receiving a signal indicating the command to capture the image from the control apparatus 3, the information processing apparatus 2 gives the image capturing apparatus 5 a command to capture the image, and accordingly, the image capturing apparatus 5 captures the image of the target 9. The information processing apparatus 2 displays an image received from the apparatus 5 image capture, on the apparatus 6 display. The information processing apparatus 2 is capable of displaying the obtained image on the display apparatus 6 along with distance information. The communication device 7 interacts with the storage device or network and stores the image in the storage device or storage on the network.

[00142] A second example of application of the SYS information processing system is an example of its application to a video information processing system that provides a mixed reality to a user. When the information processing apparatus 2 controls the range measuring apparatus 1 and the image capturing apparatus 5, the image capturing apparatus 5 captures the image of the target 9 as an object and provides it as a real image. On the other hand, the range measuring apparatus 1 provides a signal including distance information representing the distance to the target 9 as an object. The information processing apparatus 2 processes a signal and generates a composite image by combining a virtual image formed by using computer graphics and the like and a real image obtained by capturing an image capturing apparatus 5 based on distance information. The information processing apparatus 2 displays a composite image on a display apparatus 6, such as a head display.

[00143] A third example of the application of the SYS information processing system is an example of its application to transport equipment that moves under load (for example, a car or train). Upon receipt of a signal indicating a command to move the transport equipment or prepare to move it, from the control apparatus 3, which includes a device for generating a signal to start the engine (for example, a start button) and an input unit, such as a handle and accelerator, information processing apparatus 2 controls the apparatus 1 range measurement. The range measuring apparatus 1 provides a signal including distance information representing the distance to the target 9 as an object. The information processing apparatus 2 processes the signal and displays a warning on the display apparatus 6 if, for example, the distance to the target 9 becomes short. The information processing apparatus 2 is capable of displaying information representing a distance to the target 9 on the display apparatus 6. In addition, the information processing apparatus 2 is able to reduce or increase the speed of the transport equipment by controlling the drive apparatus 4, such as a brake or engine, based on the distance information. In addition, the information processing apparatus 2 is capable of adjusting the relative distance to the transport equipment that is moving forward by controlling the drive apparatus 4, such as a brake or engine, based on the distance information.

[00144] A fourth example of an application of an information processing system SYS is an example of its application to a gaming system. The user instructs the main part of the gaming machine to use the gesture mode by using the control apparatus 3, which includes an input unit, such as a controller. In response to a command from the user, the information processing apparatus 2 controls the range measuring apparatus 1. Accordingly, the distance measuring apparatus 1 detects the movement (gesture) of the user as distance information. Based on the obtained distance information, the information processing apparatus 2 creates video data in which the virtual character in the game is controlled in accordance with the movement of the user. The information processing apparatus 2 displays video data on the display apparatus 6 connected to the main part of the gaming machine (with the information processing apparatus 2).

[00145] As described above, the photoelectric conversion device 11 according to an embodiment includes a first photodiode (photoelectric conversion section 301) that generates electrons, and a second photodiode (photoelectric conversion section 302) that forms holes. In addition, the photoelectric conversion device 11 includes a first n-type semiconductor region 507 that collects electrons formed by the first photodiode (photoelectric conversion section 301) and a second p-type semiconductor region 510 that collects holes formed by the second photodiode (section 302 photoelectric conversion). In addition, the photoelectric conversion device 11 includes a signal generating portion 315 with which the first semiconductor region 507 and the second semiconductor region 510 are connected together. In addition, the photoelectric conversion device 11 includes a reference potential supply portion 411 that supplies the reference potential VF1 to the first photodiode anode 211 (photoelectric conversion section 301) and a reference potential supply portion 412 that supplies the reference potential VF2 to the second photodiode cathode 212 (photoelectric conversion section 302). The reference potential of VF2 is higher than the reference potential of VF1. Such a photoelectric conversion device is capable of accurately receiving a signal that is based on electrons and holes.

[00146] As described above, the photoelectric conversion device 11 in accordance with an embodiment includes a photoelectric conversion section 301 that forms electrons and a photoelectric conversion section 302 that forms holes. In addition, the photoelectric conversion device 11 includes an n-type semiconductor region 507 that collects electrons formed by the photoelectric conversion section 301 and a p-type semiconductor region 510 that collects holes formed by the photoelectric conversion section 302. In addition, the photoelectric conversion device 11 includes a signal generating portion 315 with which the semiconductor region 507 and the semiconductor region 510 are connected together. The difference between the first potential VS11 supplied to the semiconductor region 507 and the second potential VS12 supplied to the semiconductor region 510 during the reset period Trs is less than 0.10 V. Such a photoelectric conversion device is capable of accurately receiving a signal corresponding to the difference of the signal charge between the plurality plots of photovoltaic conversion. In addition, the photoelectric conversion device is capable of receiving in a simple configuration a signal corresponding to the difference in signal charge between the plurality of photoelectric conversion sections.

[00147] As described above, the photoelectric conversion device 11 according to an embodiment includes a photoelectric conversion section 301 that forms electrons and a photoelectric conversion section 302 that forms holes. In addition, the photoelectric conversion device 11 includes an n-type semiconductor region 507 that collects electrons formed by the photoelectric conversion section 301 and a p-type semiconductor region 510 that collects holes formed by the photoelectric conversion section 302. In addition, the photoelectric conversion device 11 includes a signal generating portion 315 with which the semiconductor region 507 and the semiconductor region 510 are connected together. The semiconductor region 507 and the semiconductor region 510 are connected to each other via a local connecting line 620, which is a conductor. With a simple configuration, such a photoelectric conversion device is capable of receiving a signal corresponding to the difference in signal charge between a plurality of photoelectric conversion sections. In addition, the photoelectric conversion device is capable of accurately receiving a signal corresponding to the difference of the signal charge between the plurality of photoelectric conversion sections.

[00148] As described above, the photoelectric conversion device 11 in accordance with an embodiment includes a photoelectric conversion section 301 that forms electrons and a photoelectric conversion section 302 that forms holes. In addition, the photoelectric conversion device 11 includes a transfer section 303 that transfers electrons formed by the photoelectric conversion section 301 to the n-type semiconductor region 507 and a transfer section 306 that transfers holes formed by the photoelectric conversion section 302 to the semiconductor region 510 p-type. In addition, the photoelectric conversion device 11 includes a signal generating portion 315 with which the semiconductor region 507 and the semiconductor region 510 are connected together. The transfer section 303 and the transfer section 306 are connected to the same transfer unit 218. At a high level of potential supplied to the transfer unit 218, the transfer section 303 is turned on and the section 306 is turned off. At a low level of potential supplied to the transfer unit 218, the transfer section 303 is turned off and the transfer section 306 is turned on. Such a photoelectric conversion device is capable of accurately receiving a signal that is based on electrons and holes. In addition, a signal that is based on electrons and holes can be obtained using a simple configuration.

[00149] As described above, the photoelectric conversion device 11 in accordance with an embodiment includes a first photodiode (photoelectric conversion section 301) that generates electrons, and a second photodiode (photoelectric conversion section 302) that forms holes. In addition, the photoelectric conversion device 11 includes a first n-type semiconductor region 507 that collects electrons formed by the first photodiode (photoelectric conversion section 301) and a second p-type semiconductor region 510 that collects holes formed by the second photodiode (section 302 photoelectric conversion). In addition, the photoelectric conversion device 11 includes a signal generating portion 315 with which the first semiconductor region 507 and the second semiconductor region 510 are connected together. The p-type semiconductor region 511 that makes up the anode 211 of the first photodiode (photoelectric conversion section 301), and the n-type semiconductor region 512 that makes up the second photodiode cathode 212 (photoelectric conversion section 302) are electrically isolated from each other by a p-n junction. With a simple configuration, such a photoelectric conversion device is capable of receiving a signal corresponding to the difference in signal charge between a plurality of photoelectric conversion sections. In addition, the photoelectric conversion device is capable of accurately receiving a signal corresponding to the difference of the signal charge between the plurality of photoelectric conversion sections.

[00150] The photoelectric conversion device is not limited to the examples described above and is applicable to various information processing systems SYS. In the above embodiment, examples have been given of examples of a photoelectric conversion device optimized for performing control for ranging, and a range measuring device and an image capturing system including the device. The photoelectric conversion device may perform control for anything other than ranging. For example, boundary detection for detecting a contour of an object such as a human face, focus detection using phase difference detection, or ranging can be performed by using a signal corresponding to a signal charge difference between a plurality of photoelectric conversion sections. Such operations can be performed since the difference in the amount of received light between the plurality of photoelectric conversion sections can be detected based on the magnitude of the output signal from the signal generating section in accordance with the difference of the signal charge. In general, a complex structure, such as a differential circuit, may be necessary to obtain the difference in electrical signals by converting the signal charge into electrical signals by using a signal conditioning portion, for example, a source follower circuit. However, the photoelectric conversion device in accordance with an embodiment is capable of easily obtaining a signal charge difference between a plurality of photoelectric conversion sections by using recombination between electrons and holes. In addition, by converting the difference of the signal charge into an electric signal using a signal generating section having a simple structure, for example, a source follower circuit, the photoelectric conversion device is capable of receiving a signal corresponding to the difference of the signal charge between the plurality of photoelectric conversion sections. By means of a switching transistor provided between the acquisition unit and the detection unit, as in the form illustrated in FIG. 7, the signal corresponding to the charge of the original signal, and not the signal corresponding to the difference between the plurality of photoelectric conversion sections, can be read separately from the signal corresponding to the difference. Accordingly, an image capturing operation can be performed.

[00151] Although the present invention has been described with reference to illustrative embodiments, it should be understood that the invention is not limited to the disclosed illustrative embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (44)

1. A photovoltaic conversion device comprising: the first section of the photoelectric conversion, which is the first photodiode and configured to form electrons; and a second photoelectric conversion section, which is a second photodiode and configured to form holes; characterized in that the photoelectric conversion device further comprises: a charge to voltage conversion section including a first n-type semiconductor region configured to collect electrons and a p-type second semiconductor region configured to collect holes; a charge to voltage conversion section is configured to convert a charge, which is based on electrons and holes, in voltage; a signal generating section configured to generate a signal corresponding to a voltage, the signal generating section including a gain transistor; a first potential supply portion configured to supply a first potential to the anode of the first photodiode; and a second potential supply portion configured to supply a second potential to the cathode of the second photodiode, the second potential being higher than the first potential. 2. The photoelectric conversion device according to claim 1, wherein the difference between the potential applied to the first semiconductor region and the potential applied to the second semiconductor region during the reset period is less than 0.10 V. 3. The photoelectric conversion device according to claim 1, further comprising a reset potential supply portion connected to the first semiconductor region via the reset transistor, a reset potential feed portion configured to supply potential to the first semiconductor region. 4. The photoelectric conversion device according to claim 3, wherein the reset potential supply portion is connected to the second semiconductor region via the reset transistor. 5. The photoelectric conversion device according to claim 1, wherein the first semiconductor region and the second semiconductor region are connected to each other through a conductor. 6. The photoelectric conversion device according to claim 1, wherein the first semiconductor region and the second semiconductor region are connected to each other via a conductor, the photoelectric conversion device further comprises a discharge potential supply portion configured to supply a discharge potential to the conductor. 7. The photoelectric conversion device according to claim 5, in which the conductor has a specific conductivity of 10 ⁴ S / m or more. 8. The photoelectric conversion device according to claim 1, wherein the first potential is lower than the zero potential and the second potential is higher than the zero potential. 9. The photoelectric conversion device according to claim 1, wherein the third p-type semiconductor region that makes up the anode of the first photodiode and the fourth n-type semiconductor region that makes up the cathode of the second photodiode are electrically isolated from each other by a p-n junction. 10. The photoelectric conversion device according to claim 9, in which the third semiconductor region and the fourth semiconductor region form a pn junction between the fifth n-type semiconductor region, which makes up the cathode of the first photodiode, and the sixth p-type semiconductor region, which makes up the anode of the second photodiode . 11. The photoelectric conversion device according to claim 1, further comprising: a first transfer portion that has a MIS gate structure and is configured to transfer the formed electrons to the first semiconductor region; and the second transfer portion, which has a MIS gate structure and is configured to transfer the formed holes into the second semiconductor region. 12. The photoelectric conversion device according to p. 11, in which the first transfer portion and the second transfer portion are connected to a common node, and the first transfer section is turned on and the second transfer section is turned off by supplying the first potential to the node, and the first transfer section is turned off and the second transfer section is turned on by supplying the second potential to the node. 13. The photovoltaic conversion device according to claim 11, further comprising: a third transfer portion, which has a MIS gate structure and is configured to transfer the formed electrons to the seventh n-type semiconductor region; and the fourth transfer portion, which has a MIS gate structure and is configured to transfer the formed holes into the eighth p-type semiconductor region. 14. The photoelectric conversion device according to claim 13, further comprising: another signal generating portion connected to the seventh semiconductor region and the eighth semiconductor region. 15. The photoelectric conversion device according to claim 14, wherein the signal generated by the signal conditioning portion and the signal generated by the other signal conditioning portion are combined. 16. The photoelectric conversion device according to any one of paragraphs. 1-15, in which the gain transistor draws up a source follower circuit, and the charge to voltage conversion portion is electrically connected to the gate electrode of the gain transistor. 17. The photoelectric conversion device according to any one of paragraphs. 1-15, in which at least one semiconductor region of the first semiconductor region and the second semiconductor region is electrically connected to the signal generating portion through at least one element of an electric low-pass filter and a transistor. 18. The photoelectric conversion device according to any one of paragraphs. 1-15, in which the section converting the charge into voltage converts the charge, which is based on the difference between the electrons collected by the first semiconductor region and the holes collected by the second semiconductor region into voltage. 19. The photoelectric conversion device according to any one of paragraphs. 1-15, wherein the first photoelectric conversion section and the second photoelectric conversion section are arranged on the semiconductor substrate in a direction along the front surface of the semiconductor substrate. 20. The photoelectric conversion device according to any one of paragraphs. 1-15, in which the first photoelectric conversion section, the second photoelectric conversion section, the charge to voltage conversion section, and the signal generation section are included in each of the cells that are arranged in the matrix. 21. A range measuring apparatus, comprising: light emitting device; and photoelectric conversion device according to any one of paragraphs. 1-15, wherein the photoelectric conversion device receives light emitted by the light emitting device. 22. The range measuring apparatus of claim 21, wherein the light emitting device flashes periodically, and electron collection in the first semiconductor region and hole collection in the second semiconductor region are alternately performed. 23. An information processing system comprising: range measuring apparatus, including a photoelectric conversion device according to any one of paragraphs. 1-15; and an information processing apparatus configured to process information obtained from a ranging apparatus. 24. The information processing system according to claim 23, wherein the information processing apparatus performs at least one process from a process for displaying information processed by the information processing apparatus on a display apparatus and a process for driving a drive apparatus based on information processed by the processing apparatus information.

Images